Diastereo- and enantioselective synthesis of orthogonally protected 2,4-diaminocyclopentanecarboxylates: a flip from beta-amino- to beta,gamma-diaminocarboxylates.

Conformationally restricted, orthogonally protected 2,4-diaminocarboxylates with a cyclopentane skeleton were efficiently synthesized from beta-lactam 6, the syntheses involving strategies of diastereoselective epoxidation of the beta-lactam and the corresponding monoprotected amino esters with opposite selectivities followed by regioselective opening of the oxirane ring with sodium azide. The enantiomers were also prepared. This new class of compounds can be regarded not only as conformationally constrained beta,gamma-diamino acid derivatives but also as potential functionalized carbocyclic nucleoside precursors.

Stereoselective synthesis of perillaldehyde-based chiral β-amino acid derivatives through conjugate addition of lithium amides.

The Michael addition of dibenzylamine to (+)-tert-butyl perillate (3) and to (+)-tert-butyl phellandrate (6), derived from (S)-(−)-perillaldehyde (1), resulted in diastereomeric β-amino esters 7A–D in a moderately stereospecific reaction in a ratio of 76:17:6:1. After separation of the diastereoisomers, the major product, cis isomer 7A, was quantitatively isomerized to the minor component, trans-amino ester 7D. All four isomers were transformed to the corresponding β-amino acids 10A–D, which are promising building blocks for the synthesis of β-peptides and 1,3-heterocycles in three steps. The steric effects of the isopropyl group at position 4 and of the α-methyl substituent of (R)-N-benzyl…

A Selective Synthesis of Fluorinated Cispentacin Derivatives

A facile selective method has been developed for the synthesis of new fluorine-containing cispentacin stereoisomers. Mono- and difluorinated cispentacin derivatives were synthetized from a bicyclic β-lactam in five or six steps involving a regio- and stereoselective hydroxylation through iodooxazoline formation, followed by deoxygenation by fluorination. Starting from an enantiomerically pure bicyclic β-lactam obtained by enzymatic resolution of the racemic compound, an enantiodivergent procedure allowed the preparation of both dextro- and levorotatory difluorinated cispentacins.

Synthesis and Conformational Analysis of Tetrahydroisoquinoline-Fused 1,3,2-Oxazaphospholidines and 1,2,3-Oxathiazol­idines

The cyclizations of tetrahydroisoquinoline 1,2-amino alcohols with phenylphosphonic dichloride, bis(2-chloroethyl)phosphoramidic dichloride, thionyl chloride and sulfuryl chloride were utilized to synthesize 1,5,6,10b-tetrahydro-1,3,2-oxazaphospholo[4,3-a]isoquinolines (2, 3), 1,5,10,10a-tetrahydro-1,3,2-oxazaphospholo[3,4-b]isoquinolines (8, 9), 1,5,6,10b-tetrahydro-1,2,3-oxathiazolo[4,3-a]isoquinolines (4–6) anda 1,5,10,10a-tetrahydro-1,2,3-oxathiazolo[3,4-b]isoquinoline (11), which are the first representatives of these ring systems. NMR spectroscopic analysis revealed the existence of conformational equilibria that are fast on the NMR timescale. Theoretical DFT calculations pointed to t…

Synthesis and conformational analysis of tetrahydroisoquinoline- and piperidine-fused 1,3,4,2-oxadiazaphosphinanes, new ring systems

Abstract Through cyclization of tetrahydroisoquinoline and piperidine 1,2-hydrazino alcohols with phenylphosphonic dichloride and phenyl dichlorophosphate, P-epimeric diastereomers of 1,6,7,11b-tetrahydro-4H-1,3,4,2-oxadiazaphosphino[5,4-a]isoquinoline-3-oxides ( 13 and 14 ), 1,6,11,11a-tetrahydro-4H-1,3,4,2-oxadiazaphosphino[4,5-b]isoquinoline-3-oxides ( 15 and 16 ) and 1,6,7,8,9,9a-hexahydro-4H-pyrido[1,2-d][1,3,4,2]oxadiazaphosphinane-3-oxides ( 17 and 18 ), the first representatives of these ring systems, were prepared. NMR and X-ray diffraction studies revealed that, independently of the P-substituent and the relative configuration of the phosphorus atom, 13 , 14 , 17 and 18 could be c…

Retro Diels Alder protocol for regioselective synthesis of novel [1,2,4]triazolo[4,3-a]pyrimidin-7(1H)-ones

Reactions of diastereochemically varied norbornene-condensed 2-thioxopyrimidin-4-ones6and10with variously functionalized hydrazonoyl chlorides2a-hgave regioselectively angular norbornene-based [1,2,4]triazolo[4,3-a]pyrimidin-7(1H)-ones7a-hand11a,c-e, respectively. Thermal retro Diels-Alder (RDA) reaction of7a-hand11a,c-eresulted in the target compounds4a-has single products. On the other hand, reactions of thiouracil1and hydrozonoyl chlorides2a-egave regioselectively [1,2,4]triazolo[4,3-a]pyrimidinone-5(1H)-ones3a-e. The opposite regioselectivity of thiouracil1and norbornene-condensed 2-thioxopyrimidin-4-ones6and10was attributed to electronic factors according to DFT calculations. The angul…

A Stereocontrolled Protocol to Highly Functionalized Fluorinated Scaffolds through a Fluoride Opening of Oxiranes

A novel selective and substrate-dependent synthetic protocol has been developed towards the synthesis of various fluorine-containing, highly functionalized cycloalkane derivatives. The method involves the stereoselective epoxidation of some unsaturated cyclic beta-amino acid derivatives as model compounds, followed by a regioselective fluoride opening of oxiranes under various conditions with Deoxofluor and XtalFluor-E reagents, thereby offering an insight into this new epoxide opening methodology with fluoride.

Regio- and stereoselective synthesis of constrained enantiomeric β-amino acid derivatives

Abstract Chlorosulfonyl isocyanate addition to (−)- and (+)-apopinene furnished monoterpene-fused β-lactams in highly regio- and stereospecific reactions. β-Lactams 5 and 13 exhibited reactivities similar to those of the cycloalkane-fused analogs and were easily converted to the β-amino acid and its protected derivatives. The base-catalyzed isomerization of the cis -amino ester afforded the corresponding trans -amino acid enantiomers in excellent yields. The complete isomerization is explained by the stability difference, which was estimated by ab initio calculations between the cis- and trans -diastereomers.

Synthesis and Conformational Analysis of Saturated3,1,2-Benzoxazaphosphinine 2-Oxides

N-Unsubstituted, N-methyl and N-benzyl cis- and trans-2(hydroxymethyl)cyclohexylamines were subjected to ring closure with phenylphosphonic dichloride, phenyl dichlorophosphate and bis(2-chloroethyl)phosphoramidic dichloride in order to synthesize P-epimeric diastereomers of the corresponding unsubsituted and N-substituted 2-phenyl-, 2phenoxy- and 2-[bis(2-chloroethyl)amino]octahydro-2H3,1,2-benzoxazaphosphinine 2-oxides. The stereochemistry and conformations of the prepared compounds were analyzed mainly by variable-temperature 1 H, 13 C and 31 P NMR spectroscopy. Geometry optimizations were performed for some trans-fused molecules by utilizing the B3LYP DFT method and a locally dense basi…

Stereoselective synthesis and application of tridentate aminodiols derived from (+)-pulegone

Abstract A library of tridentate aminodiols, derived from naturally occurring (R)-(+)-pulegone, was synthesized and applied as chiral catalysts in the addition of diethylzinc to benzaldehyde. The reduction of pulegone furnished pulegol, which was transformed into allylic trichloroacetamide via Overman rearrangement of the corresponding trichloroacetimidate. The protected enamine was subjected to dihydroxylation with OsO4/NMO system resulting in a 1:1 mixture of (1R,2R,4R)- and (1S,2S,4R)-aminodiol diastereomers. After the removal of the trichloroacetyl protecting groups, the obtained primary aminodiols were transformed into secondary ones. The regioselectivity of the ring closure of the N-b…

Chemoselective, Substrate-directed Fluorination of Functionalized Cyclopentane β-Amino Acids

This work describes a substrate-directed fluorination of some highly functionalized cyclopentane derivatives. The cyclic products incorporating CH2 F or CHF2 moieties in their structure have been synthesized from diexo- or diendo-norbornene β-amino acids following a stereocontrolled strategy. The synthetic study was based on an oxidative transformation of the ring carbon-carbon double bond of the norbornene β-amino acids, followed by transformation of the resulted "all cis" and "trans" diformyl intermediates by fluorination with "chemodifferentiation".

Synthesis of chiral 1,5-disubstituted pyrrolidinones via electrophile-induced cyclization of 2-(3-butenyl)oxazolines derived from (1R,2S)- and (1S,2R)-norephedrine

Starting from (1R,2S)- and (1S,2R)-norephedrine, enantiomers of the corresponding 2-(3-butenyl)oxazolines were prepared in a two-step process. The cyclization of the intermediate alkenylamides with phenylselenyl bromide afforded cyclic imidates instead of the expected pyrrolidinones. The electrophile-induced cyclizations of 2-alkenyloxazolines with bromine or iodine produced diastereomeric mixtures of chiral 1,5-disubstituted pyrrolidinones. The ring closure of the all-cis (1R,2S,5R)-diastereomer 7 with NaH resulted in the tetrahydropyrrolo[2,1-b]oxazol-5-one derivative 18, which was alternatively prepared by the cyclocondensation of (1R,2S)-norephedrine with levulinic acid.

Efficient regio- and stereoselective access to novel fluorinated ?-aminocyclohexanecarboxylates

A regio- and stereoselective method has been developed for the synthesis of novel fluorinated 2-aminocyclohexanecarboxylic acid derivatives with the fluorine attached to position 4 of the ring. The synthesis starts from either cis- or trans-β-aminocyclohex-4-enecarboxylic acids and involves regio- and stereoselective transformation of the ring C–C double bond through iodooxazine formation and hydroxylation, followed by hydroxy–fluorine or oxo–fluorine exchange.

Solvent-Enhanced Diastereo- and Regioselectivity in the PdII-Catalyzed Synthesis of Six- and Eight-Membered Heterocycles viacis-Aminopalladation

The Pd(II)-catalyzed intramolecular oxidative cyclization of tosyl-protected cis- and trans-N-allyl-2-aminocyclohexanecarboxamides was examined, and efficient syntheses of cyclohexane-fused pyrimidin-4-ones and 1,5-diazocin-6-ones were developed. In the course of the research, a marked solvent effect was observed on both the regio- and diastereoselectivity. Additionally, a novel Pd(II)-mediated domino oxidation, oxidative amination reaction was discovered. Our experimental and theoretical findings suggest that the reactions proceed via a cis-aminopalladation mechanism.

Synthesis of Highly Functionalized Fluorinated Cispentacin Derivatives

Fluorinated highly functionalized cispentacin derivatives were synthetised starting from an unsaturated bicyclic b-lactam through C¼C bond functionalization via the dipolar cycloaddition of a nitrile oxide, isoxazoline opening, and fluorination by OH/F exchange.

Functionalized Dialdehydes as Promising Scaffolds for Access to Heterocycles and β-Amino Acids: Synthesis of Fluorinated Piperidine and Azepane Derivatives

Functionalized dialdehydes are considered important substrates that can be transformed into various substituted heterocyclic, alicyclic, and polysubstituted compounds. Here, we report a robust stereocontrolled procedure for the synthesis of novel functionalized trifluoromethyl-containing piperidine and azepane derivatives, based on oxidative ring cleavage of the C=C bond of diversely substituted cycloalkenes, followed by reductive ring closure of the diformyl intermediates in the presence of fluorine-containing amines.

Asymmetric synthesis of α,β-diamino acid derivatives with an aziridine-, azetidine- and γ-lactone-skeleton via Mannich-type additions across α-chloro-N-sulfinylimines

The efficient asymmetric synthesis of new chiral γ-chloro-α,β-diamino acid derivatives via highly diastereoselective Mannich-type reactions of N-(diphenylmethylene) glycine esters across a chiral α-chloro-N-p-toluenesulfinylimine was developed. The influence of the base, LDA or LiHMDS, used for the formation of the glycine enolates, was of great importance for the anti-/syn-diastereoselectivity of the Mannich-type reaction. The γ-chloro-α,β-diamino acid derivatives proved to be excellent building blocks for ring closure towards optically pure anti- and syn-β,γ-aziridino-α-amino esters, and subsequent ring transformation into trans-3-aminoazetidine-2-carboxylic acid derivatives and α,β-diami…

A comparative study of the multicomponent Ugi reactions of an oxabicycloheptene-based β-amino acid in water and in methanol

Di-exo-3-amino-7-oxabicyclo[2.2.1]hept-5-ene-2-carboxylic acid 1, five aldehydes and two isocyanides were reacted both in methanol and in water to prepare a 10-membered β-lactam library via a Ugi-4-centre-3-component reaction. The yields were found to be similar in water and methanol. The diastereoselectivities of the aqueous reactions were similar, though in a few cases higher than those in methanol. The benefits of water are the facile isolation of the precipitated product and the shorter reaction time.

Fluorine-containing functionalized cyclopentene scaffolds through ring contraction and deoxofluorination of various substituted cyclohexenes

The fluorination of some highly‐functionalized cyclopentene derivatives, obtained from various substituted cyclohexenes through a ring‐opening/ring‐contraction procedure, has been investigated. The transformations were found to be highly substrate dependent, and led to the formation of various functionalized alicyclic compounds or heterocycles containing allyl difluoride or vinyl fluoride moieties. peerReviewed

Stereocontrolled synthesis of fluorine-containing piperidine γ-amino acid derivatives

An efficient synthetic approach for the construction of fluorine‐containing piperidine γ‐amino acid derivatives has been developed. The synthetic concept was based on oxidative ring opening of an unsaturated bicyclic γ‐lactam (Vince‐lactam) through its ring C=C bond, followed by double reductive amination of the diformyl intermediate performed with various fluoroalkylamines. The method has been extended towards the access of alkylated and perfluoroalkylated substances and for γ‐lactam derivatives. The transformations proceeded with stereocontrol: the configuration of the stereocenters in the products were predetermined by the configuration of the chiral centers of the starting γ‐lactam. The…

Racemization of Secondary-Amine-Containing Natural Products Using Heterogeneous Metal Catalysts

An Insight into Substrate-Dependent Fluorination of some Highly Substituted Alicyclic Scaffolds

The substrate-dependent fluorination of some highly-functionalized cyclopentane derivatives with multiple chiral centers has been investigated. The key steps of the stereocontrolled syntheses are the oxidative cleavage of the ring carbon–carbon double bond of readily available diexo or diendo norbornene β-amino acid derivatives followed by transformation of the resulted dialdehyde stereoisomers by reduction. Finally, substrate-directable chemodifferentiation of different types of hydroxy groups under fluorination procedures gave various densely functionalized alicyclic derivatives or heterocycles.

Novel functionalized cispentacin derivatives. Synthesis of 1,2,3-triazole-substituted 2-aminocyclopentanecarboxylate stereoisomers

Four 1,2,3-triazole-substituted ethyl 2-amino-3-hydroxycyclopentanecarboxylate diastereomers (3,4-disubstituted cispentacins) with a cyclopentane skeleton were prepared in enantiomerically pure form from racemic β-lactam 7 via enzymatic ring opening, epoxidation and selective ring opening of the oxirane ring with sodium azide. The formation of the 1,2,3-triazole ring system involved click chemistry: 1,3-dipolar cycloaddition of the corresponding 4-substituted azidocarboxylates with diethyl acetylenedicarboxylate.

Fluorination of some highly functionalized cycloalkanes: chemoselectivity and substrate dependence.

A study exploring the chemical behavior of some dihydroxylated β-amino ester stereo- and regioisomers, derived from unsaturated cyclic β-amino acids is described. The nucleophilic fluorinations involving hydroxy–fluorine exchange of some highly functionalized alicyclic diol derivatives have been carried out in view of selective fluorination, investigating substrate dependence, neighboring group assistance and chemodifferentiation.

Traceless chirality transfer from a norbornene β-amino acid to pyrimido[2,1-a]isoindole enantiomers

The synthesis of two enantiomeric pairs of pyrimidoisoindoles 9a, 9b and 10a, 10b is reported. During a domino ring-closure reaction, followed by cycloreversion, the chirality of diendo-(−)-(1R,2S,3R,4S)-3-aminobicyclo[2.2.1]hept-5-ene-2-carboxamide [(−)-1] was successfully transfered to heterocycles (+)-9a, (+)-10a, (−)-9b, (−)-10b and (−)-10c. peerReviewed

Synthesis of novel fluorinated building blocks via halofluorination and related reactions.

A study exploring halofluorination and fluoroselenation of some cyclic olefins, such as diesters, imides, and lactams with varied functionalization patterns and different structural architectures is described. The synthetic methodologies were based on electrophilic activation through halonium ions of the ring olefin bonds, followed by nucleophilic fluorination with Deoxo-Fluor®. The fluorine-containing products thus obtained were subjected to elimination reactions, yielding various fluorine-containing small-molecular entities.

Regio- and diastereoselective fluorination of alicyclic β-amino acids.

A regio- and stereoselective approach to fluorinated β-aminocyclohexene or cyclohexane esters has been developed, starting from a bicyclic β-lactam (1). The procedure involves six or seven steps, based on regio- and stereoselective iodolactonization, lactone opening and hydroxy–fluorine exchange. The method has been extended to the synthesis of fluorinated amino ester enantiomers.

Asymmetric synthesis of chloroisothreonine derivatives via syn-stereoselective Mannich-type additions across N-sulfinyl-α- chloroimines

Mannich-type reactions of O-Boc glycolic esters across chiral N-sulfinyl-α-chloroaldimines resulted in the efficient and syn-stereoselective synthesis of new γ-chloro-α-hydroxy-β-amino esters (dr > 99:1). The α-coordinating ability of the chlorine atom was of great importance for the diastereoselectivity of the Mannich-type reaction and overruled the chelation of the sulfinyl oxygen with the lithium ion of the incoming E-enolate in the transition state model. These novel chloroisothreonine derivatives proved to be excellent building blocks in asymmetric synthesis of novel syn-β,γ-aziridino-α-hydroxy esters and biologically relevant trans-oxazolidinone carboxylic esters.

Selective Synthesis of New Fluorinated Alicyclic β-Amino Ester Stereoisomers (Eur. J. Org. Chem. 26/2011)

The cover picture shows a waterfall located in the Eastern Carpathians in Transylvania, near Bicaz Canyon. Although fluorinated organic compounds are nonexistent in nature, an increasing number of drugs (25 %) on the market contain at least one fluorine atom. Cyclic fluorinated β-amino acid derivatives have been synthesized by selective hydroxylation and hydroxy?fluorine exchange. Details are discussed in the article by F. Fulop et al. on p. 4993 ff.

Back Cover: Chemoselective, Substrate-directed Fluorination of Functionalized Cyclopentane β-Amino Acids (Chem. Asian J. 23/2016)

Chemodiscrimination of Olefin Bonds Through Cross‐Metathesis Reactions – Synthesis of Functionalized β‐Lactam and β‐Amino Acid Derivatives

Syntheses of Four Enantiomers of 2,3-Diendo- and 3-Endo-aminobicyclo[2.2.2]oct-5-ene-2-exo-carboxylic Acid and Their Saturated Analogues

Abstract: Ethyl 2,3- diendo -3-aminobicyclo[2.2.2]oct- 5-ene-2-carboxylate ((±)- 1 ) was resolved with O , O '-dibenzoyltartaric acid via diastere omeric salt formation. The efficient synthesis of the enantiomers of 2,3- diendo -3-aminobicyclo[2.2.2]oct- 5-ene-2-carboxylic acid ((+)- 7 and (–)- 7 ), 3- endo -aminobicyclo[2.2.2]oct-5-ene-2- exo -carboxylic acid ((+)- 5 and (–)- 5 ), cis - and trans -3-aminobicyclo[2.2.2]octa ne-2-carboxylic acid ((+)- 6 , (–)- 6 , (+)- 8 and (–)- 8 ) was achieved via isomerization, hydrogenation and hydrolysis of the corresponding esters (–)- 1 and (+)- 1 . The stereochemistry and relative configurations of the synthesized compounds were determined by NMR sp…

Synthesis, in vitro activity, and three-dimensional quantitative structure-activity relationship of novel hydrazine inhibitors of human vascular adhesion protein-1.

Vascular adhesion protein-1 (VAP-1) belongs to the semicarbazide-sensitive amine oxidases (SSAOs) that convert amines into aldehydes. SSAOs are distinct from the mammalian monoamine oxidases (MAOs), but their substrate specificities are partly overlapping. VAP-1 has been proposed as a target for anti-inflammatory drug therapy because of its role in leukocyte adhesion to endothelium. Here, we describe the synthesis and in vitro activities of novel series of VAP-1 selective inhibitors. In addition, the molecular dynamics simulations performed for VAP-1 reveal that the movements of Met211, Ser496, and especially Leu469 can enlarge the ligand-binding pocket, allowing larger ligands than those s…

Synthesis of highly functionalized β-aminocyclopentanecarboxylate stereoisomers by reductive ring opening reaction of isoxazolines

A rapid and simple procedure was devised for the synthesis of multifunctionalized cyclic β-amino esters and γ-amino alcohols via the 1,3-dipolar cycloaddition of nitrile oxides to β-aminocyclopentenecarboxylates. The opening of the isoxazoline reductive ring to the corresponding highly functionalized 2-aminocyclopentanecarboxylates occurred stereoselectively with good yields.

Selective Synthesis of New Fluorinated Alicyclic β-Amino Ester Stereoisomers

New fluorinated alicyclic β-amino ester stereoisomers with a cyclohexene or cyclohexane skeleton were prepared from cis- or trans-2-aminocyclohex-3-enecarboxylic acids in five or six steps through a regio- and stereoselective hydroxylation and hydroxy–fluorine exchange. Fluorinated aminoester enantiomers were synthesized from enantiopure cis- or trans-2-aminocyclohexenecarboxylic acid (prepared byenzymatic resolution of the racemic substances).

Novel Hydrazine Molecules as Tools To Understand the Flexibility of Vascular Adhesion Protein-1 Ligand-Binding Site: Toward More Selective Inhibitors

Vascular adhesion protein-1 (VAP-1) belongs to a family of amine oxidases. It plays a role in leukocyte trafficking and in amine compound metabolism. VAP-1 is linked to various diseases, such as Alzheimer's disease, psoriasis, depression, diabetes, and obesity. Accordingly, selective inhibitors of VAP-1 could potentially be used to treat those diseases. In this study, eight novel VAP-1 hydrazine derivatives were synthesized and their VAP-1 and monoamine oxidase (MAO) inhibition ability was determined in vitro. MD simulations of VAP-1 with these new molecules reveal that the VAP-1 ligand-binding pocket is flexible and capable of fitting substantially larger ligands than was previously believ…

Fluorine-Containing Functionalized Cyclopentene Scaffolds Through Ring Contraction and Deoxofluorination of Various Substituted Cyclohexenes

Stereoselective Synthesis and Cytoselective Toxicity of Monoterpene-Fused 2-Imino-1,3-thiazines

Starting from pinane-, apopinane- and carane-based 1,3-amino alcohols obtained from monoterpene-based β-amino acids, a library of monoterpene-fused 2-imino-1,3-thiazines as main products and 2-thioxo-1,3-oxazines as side-products were prepared via two- or three-step syntheses. When thiourea adducts prepared from 1,3-amino alcohols and aryl isothiocyanates were reacted with CDI under mild conditions, O-imidazolylcarbonyl intermediates were isolated which could be transformed to the desired 1,3-thiazines under microwave conditions. 1,3-Thiazines and 2-thioxo-1,3-oxazine side-products could also be prepared in one-step reactions through the application of CDI and microwave irradiation. The rin…

An insight into the synthesis of novel aryl-substituted alicyclic β-amino acid derivatives through substrate-directed palladium-catalysed regio- and stereoselective cross-coupling

Novel aryl-substituted alicyclic β-amino acid derivatives were synthesized through substrate-determined palladium-catalysed cross-coupling of aryl iodides with five- or six-membered cycloalkene β-amino esters. The arylations were investigated with different catalysts, solvents, bases and aryl halides, and with some cyclohexene 2-aminocarboxylate isomers. The stereochemistry and the position of the ring olefinic bond of the starting 2-aminocycloalkanecarboxylate influenced the coupling reaction, and predetermined the structure of the arylated product.

Retro-Diels-Alder Protocol for the Synthesis of Pyrrolo[1,2-a]pyrimidine and Pyrimido[2,1-a]isoindole Enantiomers

A simple protocol was introduced to prepare several enantiomerically pure heterocycles by using (–)-(1R,2R,3S,4S)-3-aminonorbornene-2-carboxylic acid as a chiral auxiliary. The protocol is based on a domino ring-closure reaction, in which the relative configuration of the new asymmetric center is controlled by the stereochemistry of the amino acid, followed by a microwave-induced retro-Diels–Alder reaction.

Synthesis of Pyrrolo[1,2-a]pyrimidine Enantiomers via Domino Ring-Closure followed by Retro Diels-Alder Protocol

From 2-aminonorbornene hydroxamic acids, a simple and efficient method for the preparation of pyrrolo[1,2-a]pyrimidine enantiomers is reported. The synthesis is based on domino ring-closure followed by microwave-induced retro Diels-Alder (RDA) protocols, where the chirality of the desired products is transferred from norbornene derivatives. The stereochemistry of the synthesized compounds was proven by X-ray crystallography. The absolute configuration of the product is determined by the configuration of the starting amino hydroxamic acid. peerReviewed

Stereoselective synthesis and transformation of pinane-based 2-amino-1,3-diols

A library of pinane-based 2-amino-1,3-diols was synthesised in a stereoselective manner. Isopinocarveol prepared from (−)-α-pinene was converted into condensed oxazolidin-2-one in two steps by carbamate formation followed by a stereoselective aminohydroxylation process. The relative stereochemistry of the pinane-fused oxazolidin-2-one was determined by 2D NMR and X-ray spectroscopic techniques. The regioisomeric spiro-oxazolidin-2-one was prepared in a similar way starting from the commercially available (1R)-(−)-myrtenol (10). The reduction or alkaline hydrolysis of the oxazolidines, followed by reductive alkylation resulted in primary and secondary 2-amino-1,3-diols, which underwent a reg…

Synthesis of Highly Functionalized Cyclopentanes as Precursors of Hydroxylated Azidocarbonucleosides

Regio- and stereoisomers of functionalized azido amino alcohols with a cyclopentane skeleton were synthesized in enantiomerically pure forms. Enzymatic ring cleavage of racemic 2-azabicyclo[2.2.1]hept-5-en-3-one gave the corresponding amino acid and one enantiomer of the lactam stereospecifically. These were protected by esterification and carbamoylation, and then epoxidized. The resulting oxiranes underwent cleavage by sodium azide with complementary stereoselectivities. The regioisomeric products were easily separated by crystallization or column chromatography.

Traceless chirality transfer from a norbornene β-amino acid to pyrimido[2,1-a]isoindole enantiomers

Abstract The synthesis of two enantiomeric pairs of pyrimidoisoindoles 9a, 9b and 10a, 10b is reported. During a domino ring-closure reaction, followed by cycloreversion, the chirality of diendo-(−)-(1R,2S,3R,4S)-3-aminobicyclo[2.2.1]hept-5-ene-2-carboxamide [(−)-1] was successfully transfered to heterocycles (+)-9a, (+)-10a, (−)-9b, (−)-10b and (−)-10c.

An Easy Stereoselective Access to β,γ-Aziridino α-Amino Ester Derivatives via Mannich Reaction of Benzophenone Imines of Glycine Esters with N-Sulfonyl α-Chloroaldimines

Mannich-type addition of benzophenone imine glycinates across newly synthesized N-(p-toluenesulfonyl) alpha-chloroaldimines afforded gamma-chloro-alpha,beta-diamino ester derivatives with moderate diastereoselectivity as separable mixtures of anti and syn diastereomers. The gamma-chloro-alpha,beta-diamino esters were efficiently cyclized under basic conditions to the corresponding beta,gamma-aziridino alpha-amino ester derivatives, representing a new class of conformationally constrained heterocyclic alpha,beta-diamino acid derivatives. The relative configuration of the aziridines was determined via X-ray diffraction analysis. Mechanisms and intermediate transition states to explain the ste…

Synthesis of conformationally restricted 1,2,3-triazole-substituted ethyl β- and γ-aminocyclopentanecarboxylate stereoisomers. Multifunctionalized alicyclic amino esters

Abstract Stereoisomers of 1,2,3-triazole-functionalized, conformationally restricted β- or γ-amino esters with a cyclopentane skeleton were efficiently synthetized from the bicyclic β-lactam 6-azabicyclo[3.2.0]hept-3-en-7-one (1) and Vince γ-lactam (15) in five or six steps involving the azide–alkyne 1,3-dipolar cycloaddition of azido-substituted amino ester stereoisomers with nonsymmetric acetylenes. The azide–alkyne click reactions were investigated under thermal and Cu(I)-catalyzed conditions. Surprisingly, the thermally induced cycloaddition furnished the corresponding 1,4-triazoles regioselectively, which also took place selectively in response to Cu(I) catalysis.

Olefin-Bond Chemodifferentiation through Cross-Metathesis Reactions: A Stereocontrolled Approach to Functionalized β2,3 -Amino Acid Derivatives

Microwave-assisted, highly enantioselective addition of diethylzinc to aromatic aldehydes catalyzed by chiral aminonaphthols

Abstract New optically active aminonaphthols were obtained by condensation of 2-naphthol, benzaldehyde and ( R )-(+)-1-(1-naphthyl)ethylamine or ( R )-(+)-1-(2-naphthyl)ethylamine. Their N-methylated derivatives were also synthesized. The new aminonaphthols 2 , 4 , 5 and 7 were found to catalyze the enantioselective ethylation of aryl aldehydes to 1-aryl-1-propanols (up to 92% ee). The reactions were accelerated greatly by microwave irradiation.

Synthesis and stereochemical studies of 1- and 2-phenyl-substituted 1,3-oxazino[4,3-a]isoquinoline derivatives

Abstract Starting from the 1′- or 2′-phenyl-substituted 1-(2′-hydroxyethyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline diastereomers 3 and 6 , 4-unsubstituted and 4-(p-nitrophenyl)- and 4-oxo-substituted 1-phenyl- and 2-phenyl-9,10-dimethoxy-2H,4H-1,6,7,11b-tetrahydro-1,3-oxazino[4,3-a]isoquinolines ( 7–12 ) were prepared. The relative configurations and the predominant conformations of the products were determined by NMR spectroscopy, by quantum chemical calculations and, for (2R∗,4S∗,11bR∗)-9,10-dimethoxy-4-(p-nitrophenyl)-2-phenyl-2H,4H-1,6,7,11b-tetrahydro-1,3-oxazino[4,3-a]isoquinoline ( 11 ), by X-ray diffraction.

Stereocontrolled Synthesis of Fluorine-Containing Piperidine γ-Amino Acid Derivatives

Front Cover: Stereocontrolled Synthesis of Fluorine-Containing Piperidine γ-Amino Acid Derivatives (Eur. J. Org. Chem. 12/2019)

Synthesis of novel functionalized cispentacins through C–C oxidative cleavage of diendo-norbornene β-amino acid

Difunctionalized cispentacin derivatives with two new stereogenic centres have been synthesized from a diendo-norbornene β-amino acid in a stereocontrolled route, involving C–C double bond functionalization by dihydroxylation, followed by oxidative ring cleavage and transformation of the dialdehyde intermediates through a Wittig reaction.

A Domino Ring‐Closure Followed by Retro‐Diels–Alder Reaction for the Preparation of Pyrimido[2,1‐ a ]isoindole Enantiomers

A simple method was developed to prepare pyrimido[2,1-a]isoindole derivatives by using di-endo- and di-exo-ethyl 3-aminobicyclo[2.2.1]hept-5-ene-2-carboxylate enantiomers as chiral sources. The method is based on a domino ring-closure reaction of norbornene 2-aminohydroxamic acid followed by microwave-induced retro-Diels–Alder reaction. In the case of enantiomeric starting substances, the chirality is transferred from norbornene derivatives to pyrimido[2,1-a]isoindoles. The configurations of the synthesized compounds were determined by 1D and 2D NMR spectroscopy [based on 2D NOE cross-peaks and 3JH,H coupling constants] and X-ray crystallography.

Synthesis and biological evaluation of the new ring system benzo[f]pyrimido[1,2-d][1,2,3]triazolo[1,5-a][1,4]diazepine and its cycloalkane and cycloalkene condensed analogues

Derivatives of the new ring system benzo[f]pyrimido[1,2-d][1,2,3]triazolo[1,5-a][1,4]diazepinone and its cycloalkane and cycloalkene condensed analogues have been conveniently synthesized through a three-step reaction sequence. An atom-economical, one-pot, three-step cascade process engaging five reactive centers (amide, amine, carbonyl, azide, and alkyne) has been performed for the synthesis of alicyclic derivatives of quinazolinotriazolobenzodiazepine using cyclohexane, cyclohexene, and norbornene β-amino amides. The stereochemistry and relative configurations of the synthesized compounds were determined by 1D and 2D NMR spectroscopy and X-ray crystallography. The reaction was also perfor…

Synthesis of mono- and dihydroxy-substituted 2-aminocyclooctanecarboxylic acid enantiomers

Abstract (1R,2S,6R)-2-Amino-6-hydroxycyclooctanecarboxylic acid (−)-10 was synthesized from (1R,2S)-2-aminocyclooct-5-enecarboxylic acid (+)-2 via an iodolactone intermediate, while (1R,2S,3R,4S)-2-amino-5,6-dihydroxycyclooctanecarboxylic acid (−)-12 was prepared by using the OsO4-catalyzed oxidation of Boc-protected amino ester (−)-5. The stereochemistry and relative configurations of the synthesized compounds were determined by 1D and 2D NMR spectroscopy (based on 2D NOE cross-peaks and 3J(H,H) coupling constants) and X-ray crystallography.

Stereocontrolled synthesis of five diastereomers of trimethyl 3-aminocyclopentane-1,2,4-tricarboxylates

Abstract The sterically controlled oxidative cleavage of N - protected di exo - and di endo -substituted norbornene β-amino acids/esters resulted in four trimethyl 3-aminocyclopentane-1,2,4-carboxylate diastereomers. The sodium methoxide mediated isomerization of the four diastereomers in all cases yielded the thermodynamically most stable all- trans stereoisomer as a single product.

Regio- and stereoselective synthesis of the enantiomers of monoterpene-based β-amino acid derivatives

Abstract The regio- and stereospecific addition of chlorosulfonyl isocyanate to cis-δ-pinene enantiomers has furnished monoterpene-fused β-lactams. The observed regioselectivity can be explained by ab initio DFT modeling of transition state structures. In contrast with the less reactive α-pinane-fused β-lactam 4, the resulting β-lactams 5 and 13 containing an amino group connected to a secondary carbon possess similar reactivity to the cycloalkane-fused analogues and can be easily converted to the β-amino acid and its protected derivatives. The base-catalyzed isomerization of the cis-amino ester afforded the corresponding trans-amino ester in moderate yield.

Synthesis of novel isoxazoline-fused cispentacin stereoisomers

Abstract New isoxazoline-fused cispentacins were prepared by the 1,3-dipolar cycloaddition of nitrile oxides to β-amino esters containing a cyclopentene skeleton. This synthetic procedure gave regio- and diastereoisomers of the cispentacins. The synthetic route was extended to the synthesis of these compounds in enantiomerically pure form.

Synthesis of fluorinated piperidine and azepane β-amino acid derivatives

Abstract A convenient and robust stereocontrolled procedure has been developed for the synthesis of novel trifluoromethyl-containing piperidine and azepane β-amino ester stereoisomers. The synthesis started from readily available unsaturated bicyclic β-lactams and was based on oxidative cleavage of the ring C C double bond followed by ring closure of the diformyl intermediates in the presence of 2,2,2-trifluoroethylamine hydrochloride through reductive amination. The synthetic procedure has efficiently been extended towards the synthesis of mono- and difluorinated analogs.

Angular Regioselectivity in the Reactions of 2-Thioxopyrimidin-4-ones and Hydrazonoyl Chlorides : Synthesis of Novel Stereoisomeric Octahydro[1,2,4]triazolo[4,3-a]quinazolin-5-ones

The regioselective synthesis of cis and trans stereoisomers of variously functionalized octahydro[1,2,4]triazolo[4,3-a]quinazolin-5-ones was performed. The 2-thioxopyrimidin-4-ones used in the synthesis reacted with hydrazonoyl chlorides in a regioselective manner to produce the angular regioisomers [1,2,4]triazolo[4,3-a]quinazolin-5-ones rather than the linear isomers [1,2,4]triazolo[4,3-a]quinazolin-5-ones. The synthesis process took place with electronic control. The angular regiochemistry of the products was confirmed by X-ray experiments and two-dimensional NMR studies.

Selective nitrile oxide dipolar cycloaddition for the synthesis of highly functionalized β-aminocyclohexanecarboxylate stereoisomers

Highly functionalized β-aminocyclohexanecarboxylate regio- and stereoisomers were synthesized from a bicyclic β-lactam by successive regioselective iodolactonization, stereo- and regioselective nitrile oxide cycloaddition, lactone ring-opening and isoxazoline ring-opening.

A novel and selective fluoride opening of aziridines by XtalFluor-E. synthesis of fluorinated diamino acid derivatives.

The selective introduction of fluorine onto the skeleton of an aminocyclopentane or cyclohexane carboxylate has been developed through a novel and efficient fluoride opening of an activated aziridine ring with XtalFluor-E. The reaction proceeded through a stereoselective aziridination of the olefinic bond of a bicyclic lactam and regioselective aziridine ring opening with difluorosulfiliminium tetrafluoroborate with the neighboring group assistance of the sulfonamide moiety to yield fluorinated diamino acid derivatives. The method based on the selective aziridine opening by fluoride has been generalized to afford access to mono- or bicyclic fluorinated substances.

Synthesis of fluorinated amino acid derivatives through late-stage deoxyfluorinations

Abstract Fluorine chemistry has represented a hot topic in drug research over the last decade. Because of their pharmaceutical potential, fluorine-containing amino acids and related derivatives have acquired high importance among medicinal chemists. Therefore their synthesis and the development of various synthetic methods for these types of molecular scaffolds have gained increasing interest in synthetic organic chemistry. The current review focuses on synthetic protocols towards fluorine-containing amino acid derivatives through late-stage fluorination with various nucleophilic reagents, describing the access of various open-chain and cyclic α-, β-, γ-amino acid derivatives.

Synthesis of densely functionalized cispentacin derivatives through selective aziridination and aziridine opening reactions: Orthogonally protected di- and triaminocyclopentanecarboxylates

A novel substrate-directed synthetic route to a series of highly functionalized, orthogonally protected di- or triaminocyclopentanecarboxylate derivatives with multiple chiral centres from an unsaturated bicyclic β-lactam has been accomplished by applying stereoselective ring C–C double bond aziridination with chloramine-T and phenyltrimethylammonium tribromide, followed by regioselective aziridine opening with different N,O nucleophiles and hydrides. The functionalization strategy was successfully extended for access to enantiomerically pure orthogonally protected triaminocarboxylates.

Substrate-dependent fluorinations of highly functionalized cycloalkanes

Abstract Substrate-dependent fluorinations of several highly functionalized cycloalkanes with multiple stereocentres were investigated. The synthetic transformations were based on selective functionalization of the ring C C bonds of the readily available bicyclic β-lactams by epoxidation and regioselective nucleophilic oxirane opening with azide or cyanide, followed by hydroxy–fluorine exchange with Deoxofluor. Depending on the substituents and their relative steric arrangement, the attempted fluorinations produced different types of substituted cycloalkanes. These selective, substrate-directed synthetic procedures and their presumed pathways towards interesting highly functionalized fluori…

Synthesis and biological evaluation of the new ring system benzo[f]pyrimido[1,2-d][1,2,3]triazolo[1,5-a][1,4]diazepine and its cycloalkane and cycloalkene condensed analogues

Derivatives of the new ring system benzo[f]pyrimido[1,2-d][1,2,3]triazolo[1,5-a][1,4]diazepinone and its cycloalkane and cycloalkene condensed analogues have been conveniently synthesized through a three-step reaction sequence. An atom-economical, one-pot, three-step cascade process engaging five reactive centers (amide, amine, carbonyl, azide, and alkyne) has been performed for the synthesis of alicyclic derivatives of quinazolinotriazolobenzodiazepine using cyclohexane, cyclohexene, and norbornene β-amino amides. The stereochemistry and relative configurations of the synthesized compounds were determined by 1D and 2D NMR spectroscopy and X-ray crystallography. The reaction was also perfor…

Stereoselective synthesis of carane-based chiral β- and γ-amino acid derivatives via conjugate addition

Abstract Michael addition of dibenzylamine to (−)-tert-butyl isochaminate, prepared in three steps from (−)-perillaldehyde, furnished a carane-based β-amino acid derivative in a highly stereospecific reaction. The resulting amino ester was transformed to the bicyclic amino acid, a promising building block for the synthesis of 1,3-heterocycles and peptidomimetics. The conjugate addition of nitromethane to α,β-unsaturated methyl ester likewise resulted in nitro esters in stereospecific reactions. Catalytic reduction of the nitro group yielded a γ-amino ester. Under acidic conditions, the hydrolysis of the methyl ester resulted in an unexpected aminolactone-type product through rearrangement o…

CCDC 919638: Experimental Crystal Structure Determination

Related Article: Maria Cherepanova, Loránd Kiss, Reijo Sillanpää, Ferenc Fülöp|2013|RSC Advances|3|9757|doi:10.1039/C3RA41963K

CCDC 1495998: Experimental Crystal Structure Determination

Related Article: Loránd Kiss, Melinda Nonn, Reijo Sillanpää, Matti Haukka, Santos Fustero, Ferenc Fülöp|2016|Chem.Asian J.|11|3376|doi:10.1002/asia.201601046

CCDC 1456785: Experimental Crystal Structure Determination

Related Article: Beáta Fekete, Márta Palkó, István Mándity, Matti Haukka, Ferenc Fülöp|2016|Eur.J.Org.Chem.|2016|3519|doi:10.1002/ejoc.201600434

CCDC 922681: Experimental Crystal Structure Determination

Related Article: Ferenc Miklós, István M. Mándity, Reijo Sillanpää, Ferenc Fülöp|2013|Tetrahedron Lett.|54|3769|doi:10.1016/j.tetlet.2013.05.009

CCDC 977961: Experimental Crystal Structure Determination

Related Article: Gert Callebaut, Filip Colpaert, Melinda Nonn, Loránd Kiss, Reijo Sillanpää, Karl W. Törnroos, Ferenc Fülöp, Norbert De Kimpe, Sven Mangelinckx|2014|Org.Biomol.Chem.|12|3393|doi:10.1039/C4OB00243A

CCDC 1562225: Experimental Crystal Structure Determination

Related Article: Attila Márió Remete, Melinda Nonn, Santos Fustero, Matti Haukka, Ferenc Fülöp, Loránd Kiss|2017|Beilstein J.Org.Chem.|13|2364|doi:10.3762/bjoc.13.233

CCDC 1814087: Experimental Crystal Structure Determination

Related Article: Attila Márió Remete, Melinda Nonn, Santos Fustero, Matti Haukka, Ferenc Fülöp, Loránd Kiss|2018|Eur.J.Org.Chem.|2018|3735|doi:10.1002/ejoc.201800057

CCDC 2048904: Experimental Crystal Structure Determination

Related Article: Mohamed El Haimer, Márta Palkó, Matti Haukka, Márió Gajdács, István Zupkó, Ferenc Fülöp|2021|RSC Advances|11|6952|doi:10.1039/D0RA10553H

CCDC 1508564: Experimental Crystal Structure Determination

Related Article: Beáta Fekete, Márta Palkó, Matti Haukka, Ferenc Fülöp|2017|Molecules|22|613|doi:10.3390/molecules22040613

CCDC 1057565: Experimental Crystal Structure Determination

Related Article: Melinda Nonn, Loránd Kiss, Matti Haukka, Santos Fustero, Ferenc Fülöp|2015|Org.Lett.|17|1074|doi:10.1021/acs.orglett.5b00182

CCDC 2011188: Experimental Crystal Structure Determination

Related Article: Attila Márió Remete, Tamás T Novák, Melinda Nonn, Matti Haukka, Ferenc Fülöp, Loránd Kiss|2020|Beilstein J.Org.Chem.|16|2562|doi:10.3762/bjoc.16.208

CCDC 924270: Experimental Crystal Structure Determination

Related Article: Ferenc Miklós, Zita Tóth, Mikko M. Hänninen, Reijo Sillanpää, Enikő Forró and Ferenc Fülöp|2013|Eur.J.Org.Chem.|2013|4887|doi:10.1002/ejoc.201300452

CCDC 1401005: Experimental Crystal Structure Determination

Related Article: Loránd Kiss, Attila Márió Remete, Melinda Nonn, Santos Fustero, Reijo Sillanpää, Ferenc Fülöp|2016|Tetrahedron|72|781|doi:10.1016/j.tet.2015.12.017

CCDC 1000178: Experimental Crystal Structure Determination

Related Article: Zsolt Szakonyi, István Zupkó, Reijo Sillanpää and Ferenc Fülöp|2014|Molecules|19|15918|doi:10.3390/molecules191015918

CCDC 924268: Experimental Crystal Structure Determination

Related Article: Ferenc Miklós, Zita Tóth, Mikko M. Hänninen, Reijo Sillanpää, Enikő Forró and Ferenc Fülöp|2013|Eur.J.Org.Chem.|2013|4887|doi:10.1002/ejoc.201300452

CCDC 1470051: Experimental Crystal Structure Determination

Related Article: Tímea Gonda, Zsolt Szakonyi, Antal Csámpai, Matti Haukka, Ferenc Fülöp|2016|Tetrahedron:Asymm.|27|480|doi:10.1016/j.tetasy.2016.04.009

CCDC 922680: Experimental Crystal Structure Determination

Related Article: Ferenc Miklós, István M. Mándity, Reijo Sillanpää, Ferenc Fülöp|2013|Tetrahedron Lett.|54|3769|doi:10.1016/j.tetlet.2013.05.009

CCDC 1038709: Experimental Crystal Structure Determination

Related Article: Melinda Nonn, Loránd Kiss, Mikko M. Hänninen, Ferenc Fülöp|2015|RSC Advances|5|13628|doi:10.1039/C4RA16196C

CCDC 924269: Experimental Crystal Structure Determination

Related Article: Ferenc Miklós, Zita Tóth, Mikko M. Hänninen, Reijo Sillanpää, Enikő Forró and Ferenc Fülöp|2013|Eur.J.Org.Chem.|2013|4887|doi:10.1002/ejoc.201300452

CCDC 1964840: Experimental Crystal Structure Determination

Related Article: Ferenc Miklós, Kristof Bozó, Zsolt Galla, Matti Haukka, Ferenc Fülöp|2017|Tetrahedron:Asymm.|28|1401|doi:10.1016/j.tetasy.2017.07.006

CCDC 977962: Experimental Crystal Structure Determination

Related Article: Gert Callebaut, Filip Colpaert, Melinda Nonn, Loránd Kiss, Reijo Sillanpää, Karl W. Törnroos, Ferenc Fülöp, Norbert De Kimpe, Sven Mangelinckx|2014|Org.Biomol.Chem.|12|3393|doi:10.1039/C4OB00243A

CCDC 1964839: Experimental Crystal Structure Determination

Related Article: Ferenc Miklós, Kristof Bozó, Zsolt Galla, Matti Haukka, Ferenc Fülöp|2017|Tetrahedron:Asymm.|28|1401|doi:10.1016/j.tetasy.2017.07.006

CCDC 1508563: Experimental Crystal Structure Determination

Related Article: Beáta Fekete, Márta Palkó, Matti Haukka, Ferenc Fülöp|2017|Molecules|22|613|doi:10.3390/molecules22040613

CCDC 2011187: Experimental Crystal Structure Determination

Related Article: Attila Márió Remete, Tamás T Novák, Melinda Nonn, Matti Haukka, Ferenc Fülöp, Loránd Kiss|2020|Beilstein J.Org.Chem.|16|2562|doi:10.3762/bjoc.16.208

CCDC 2063843: Experimental Crystal Structure Determination

Related Article: Ákos Bajtel, Mounir Raji, Matti Haukka, Ferenc Fülöp, Zsolt Szakonyi|2021|Beilstein J.Org.Chem.|17|983|doi:10.3762/bjoc.17.80

CCDC 1495999: Experimental Crystal Structure Determination

Related Article: Loránd Kiss, Melinda Nonn, Reijo Sillanpää, Matti Haukka, Santos Fustero, Ferenc Fülöp|2016|Chem.Asian J.|11|3376|doi:10.1002/asia.201601046

CCDC 924267: Experimental Crystal Structure Determination

Related Article: Ferenc Miklós, Zita Tóth, Mikko M. Hänninen, Reijo Sillanpää, Enikő Forró and Ferenc Fülöp|2013|Eur.J.Org.Chem.|2013|4887|doi:10.1002/ejoc.201300452

CCDC 1508562: Experimental Crystal Structure Determination

Related Article: Beáta Fekete, Márta Palkó, Matti Haukka, Ferenc Fülöp|2017|Molecules|22|613|doi:10.3390/molecules22040613

CCDC 2063842: Experimental Crystal Structure Determination

Related Article: Ákos Bajtel, Mounir Raji, Matti Haukka, Ferenc Fülöp, Zsolt Szakonyi|2021|Beilstein J.Org.Chem.|17|983|doi:10.3762/bjoc.17.80

CCDC 2011186: Experimental Crystal Structure Determination

Related Article: Attila Márió Remete, Tamás T Novák, Melinda Nonn, Matti Haukka, Ferenc Fülöp, Loránd Kiss|2020|Beilstein J.Org.Chem.|16|2562|doi:10.3762/bjoc.16.208

CCDC 1964841: Experimental Crystal Structure Determination

Related Article: Ferenc Miklós, Kristof Bozó, Zsolt Galla, Matti Haukka, Ferenc Fülöp|2017|Tetrahedron:Asymm.|28|1401|doi:10.1016/j.tetasy.2017.07.006

CCDC 982910: Experimental Crystal Structure Determination

Related Article: Loránd Kiss, Melinda Nonn, Enikő Forró, Reijo Sillanpää, Santos Fustero, Ferenc Fülöp|2014|Eur.J.Org.Chem.|2014|4070|doi:10.1002/ejoc.201402121

CCDC 977960: Experimental Crystal Structure Determination

Related Article: Gert Callebaut, Filip Colpaert, Melinda Nonn, Loránd Kiss, Reijo Sillanpää, Karl W. Törnroos, Ferenc Fülöp, Norbert De Kimpe, Sven Mangelinckx|2014|Org.Biomol.Chem.|12|3393|doi:10.1039/C4OB00243A

CCDC 1814088: Experimental Crystal Structure Determination

Related Article: Attila Márió Remete, Melinda Nonn, Santos Fustero, Matti Haukka, Ferenc Fülöp, Loránd Kiss|2018|Eur.J.Org.Chem.|2018|3735|doi:10.1002/ejoc.201800057

CCDC 1040501: Experimental Crystal Structure Determination

Related Article: Zsolt Szakonyi, Árpád Csőr, Matti Haukka, Ferenc Fülöp|2015|Tetrahedron|71|4846|doi:10.1016/j.tet.2015.05.019

CCDC 2048905: Experimental Crystal Structure Determination

Related Article: Mohamed El Haimer, Márta Palkó, Matti Haukka, Márió Gajdács, István Zupkó, Ferenc Fülöp|2021|RSC Advances|11|6952|doi:10.1039/D0RA10553H

CCDC 982909: Experimental Crystal Structure Determination

Related Article: Loránd Kiss, Melinda Nonn, Enikő Forró, Reijo Sillanpää, Santos Fustero, Ferenc Fülöp|2014|Eur.J.Org.Chem.|2014|4070|doi:10.1002/ejoc.201402121

CCDC 2048906: Experimental Crystal Structure Determination

Related Article: Mohamed El Haimer, Márta Palkó, Matti Haukka, Márió Gajdács, István Zupkó, Ferenc Fülöp|2021|RSC Advances|11|6952|doi:10.1039/D0RA10553H

CCDC 1040500: Experimental Crystal Structure Determination

Related Article: Zsolt Szakonyi, Árpád Csőr, Matti Haukka, Ferenc Fülöp|2015|Tetrahedron|71|4846|doi:10.1016/j.tet.2015.05.019

CCDC 1964842: Experimental Crystal Structure Determination

Related Article: Ferenc Miklós, Kristof Bozó, Zsolt Galla, Matti Haukka, Ferenc Fülöp|2017|Tetrahedron:Asymm.|28|1401|doi:10.1016/j.tetasy.2017.07.006

CCDC 1008231: Experimental Crystal Structure Determination

Related Article: Melinda Nonn, Loránd Kiss, Enikő Forró, Reijo Sillanpää, Ferenc Fülöp|2014|Tetrahedron|70|8511|doi:10.1016/j.tet.2014.09.071

CCDC 1470052: Experimental Crystal Structure Determination

Related Article: Tímea Gonda, Zsolt Szakonyi, Antal Csámpai, Matti Haukka, Ferenc Fülöp|2016|Tetrahedron:Asymm.|27|480|doi:10.1016/j.tetasy.2016.04.009

CCDC 1456786: Experimental Crystal Structure Determination

Related Article: Beáta Fekete, Márta Palkó, István Mándity, Matti Haukka, Ferenc Fülöp|2016|Eur.J.Org.Chem.|2016|3519|doi:10.1002/ejoc.201600434

CCDC 1057564: Experimental Crystal Structure Determination

Related Article: Melinda Nonn, Loránd Kiss, Matti Haukka, Santos Fustero, Ferenc Fülöp|2015|Org.Lett.|17|1074|doi:10.1021/acs.orglett.5b00182

CCDC 1000179: Experimental Crystal Structure Determination

Related Article: Zsolt Szakonyi, István Zupkó, Reijo Sillanpää and Ferenc Fülöp|2014|Molecules|19|15918|doi:10.3390/molecules191015918