Search results for "synteesi"
showing 10 items of 132 documents
Synthesis of trans-disubstituted-2,3-dihydrobenzofurans by a formal [4 + 1] annulation between para-quinone methides and sulfonium salts
2018
An efficient protocol for the synthesis of trans-disubstituted-2,3-dihydrobenzofurans through [4 + 1] annulation of para-quinone methides with sulfonium salts has been developed. Under very mild conditions this unprecedented reaction occurs in good to excellent yields (up to 99%), offering a straightforward access to a variety of 2,3-dihydrobenzofurans.
Angular Regioselectivity in the Reactions of 2-Thioxopyrimidin-4-ones and Hydrazonoyl Chlorides : Synthesis of Novel Stereoisomeric Octahydro[1,2,4]t…
2020
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.
Synthesis of Unexpected Dimethyl 2-(4-Chlorophenyl)-2,3-dihydropyrrolo[2,1-a]isoquinoline-1,3-dicarboxylate via Hydrolysis/Cycloaddition/Elimination …
2021
Hydrolysis/[3 + 2] cycloaddition/elimination cascades employed for the synthesis of unexpected tricyclic compound derived from isoquinoline. Reaction of ethylene derivative 1 with the isoquinoline ester iminium ion 2 in alkaline medium (MeOH/NEt3) under reflux for 1 h resulted in the formation of the fused pyrrolo[2,1-a]isoquinoline derivative 3. Its structure was elucidated by X-ray single crystal and other spectrophotometric tools. Hirshfeld calculations for 3 and its crystal structure analysis revealed the importance of the short O…H (19.1%) contacts and the relatively long H…C (17.1%), Cl…H (10.6%) and C…C (6.1%) interactions in the molecular packing. DFT calculations were used to compu…
Acetic Acid Mediated for One-Pot Synthesis of Novel Pyrazolyl s-Triazine Derivatives for the Targeted Therapy of Triple-Negative Breast Tumor Cells (…
2022
Here, we described the synthesis of novel pyrazole-s-triazine derivatives via an easy one-pot procedure for the reaction of β-dicarbonyl compounds (ethylacetoacetate, 5,5-dimethyl-1,3-cyclohexadione or 1,3-cyclohexadionone) with N,N-dimethylformamide dimethylacetal, followed by addition of 2-hydrazinyl-4,6-disubstituted-s-triazine either in ethanol-acetic acid or neat acetic acid to afford a novel pyrazole and pyrazole-fused cycloalkanone systems. The synthetic protocol proved to be efficient, with a shorter reaction time and high chemical yield with broad substrates. The new pyrazolyl-s-triazine derivatives were tested against the following cell lines: MCF-7 (breast cancer); MDA-MB-231 (tr…
Synthesis of a Novel Hydrazone of Thieno[2,3-d]pyrimidine Clubbed with Ninhydrin: X-ray Crystal Structure and Computational Investigations
2023
The novel hydrazone-containing thieno[2,3-d]pyrimidine, namely, N′-(1,3-dioxo-1,3-dihydro-2H-inden-2-ylidene)-2-(4-oxo-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-3(4H)-yl)acetohydrazide 4 was synthesized in a very good yield from the reaction of the triketoester 1 or ninhydrin 2 with the exocyclic acetohydrazide 3 in methanol. Good-quality crystals of 4 were obtained by recrystallization of the compound from the DMF/MeOH solvent mixture. The target product 4 crystallized in the triclinic crystal system and P-1 space group. The topology analysis of molecular packing indicated that the H…H (30.4%), O…H (22.0%) and H…C (17.0%) contacts are the most dominant i…
Stereoselective Synthesis of New 4-Aryl-5-indolyl-1,2,4-triazole S- and N-β-Galactosides: Characterizations, X-ray Crystal Structure and Hirshfeld Su…
2023
5-(1H-Indol-2-yl)-4-phenyl-2,4-dihydro-3H-1,2,4-triazole-3-thione 1a and 4-(4-chlorophenyl)-5-(1H-indol-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione 1b were galactosylated in the presence of NaHCO3 in ethanol to produce S-galactosides 3,4, whereas, in the presence of K2CO3 in acetone they produced a mixture of S- and N-galactosides 3-6 with a higher yield of S-galactosides over the respective N-galactosides. Improvement in the yields of N-galactosides was produced by thermal migration of the galactosyl moiety from sulfur to nitrogen using fusion. β-Stereoselectivity of galactosylation was determined using the coupling constant value 3J1,2, which exceeded 9.0 Hz in all prepared galactos…
[3 + 2] Cycloadditions in Asymmetric Synthesis of Spirooxindole Hybrids Linked to Triazole and Ferrocene Units: X-ray Crystal Structure and MEDT Stud…
2022
Derivatization of spirooxindole having triazole and ferrocene units was achieved by the [3 + 2] cycloaddition (32CA) reaction approach. Reacting the respective azomethine ylide (AY) intermediate generated in situ with the ethylene derivative produced novel asymmetric cycloadducts with four contiguous asymmetric carbons in an overall high chemical yield with excellent regioselectivity and diastereoselectivity. X-Ray single-crystal structure analyses revealed, with no doubt, the success of the synthesis of the target compounds. The 32CA reaction of AY 5b with ferrocene ethylene 1 has been studied within MEDT. This 32CA reaction proceeds via a two-stage one-step mechanism involving a high asyn…
Formal synthesis of ent-Cephalotaxine using a one-pot Parham-aldol sequence
2018
A short formal synthesis of ent-Cephalotaxine is achieved. The approach features a new Lewis acid mediated [2,3]-Stevens rearrangement of N-allylated prolineamide to generate a key quaternary stereogenic center. Additionally, a one-pot Parham–aldol sequence was developed to rapidly assembly two of the four rings in the cephalotaxine core. peerReviewed
Synthetic studies on 1-azabicyclo[5.3.0]decane alkaloids
2018
The first chapter introduces the reader to the concept of natural product total synthesis and its importance to chemistry, other sciences, and society. The second chapter reviews the chemistry of natural products containing 1-azabicyclo[5.3.0]decane motifs. This bicyclic motif and the natural products related to it, have been a continuous source of synthetic inspiration over the last decades. The second chapter of the thesis reviews the strategies and tactics developed. The third chapter covers the author’s total synthesis of stemoamide, a 1-azabicyclo[5.3.0]decane motif containing alkaloid. Additionally, two diastereomers of stemoamide were synthesized, allowing their structural reassignme…
One-Pot Synthesis, X-ray Single Crystal and Molecular Insight of Enaminone-Based β-Morpholino-/N-Methylpiperazinyl-/Pyrrolidinylpropiophenone
2020
One-pot synthesis of three enaminones, (E)-1-(4-chlorophenyl)-3-morpholinoprop-2-en-1-one 1, (E)-1-(4-chlorophenyl)-3-(4-methylpiperazin-1-yl)prop-2-en-1-one 2, and (E)-1-(4-chlorophenyl)-3-(pyrrolidin-1-yl)prop-2-en-1-one 3 were achieved. The synthetic protocol via three components reaction of p-chloroacetophenone with DMFDMA (N,N-dimethylformamid-dimethylacetal) and the corresponding secondary amines (morpholine/N-methylpiperazine/pyrrolidine) in dioxane under heating for 2.5–4 h at 102 °C yielded the requisite enaminones. This protocol has the advantage of no separation of intermediate, no need for column purification with quantitative yield for the target compounds. The chemical feature…