8-Iodonaphthalene-1-carbaldehyde: A Versatile Building Block for Diversity-Oriented Synthesis.

The scarcely studied 8-halonaphthalene-1-carbaldehyde structure has been converted into the corresponding Ellman’s imine and subjected to several transformations, thus achieving an assorted library of polycyclic carbo- and heterocycles. The potential of this scaffold for Diversity-Oriented Synthesis has been shown. Most of these skeletons are unprecedented and, therefore, cover unexplored regions of the chemical space.

Recent progress in the application of fluorinated chiral sulfinimine reagents

Abstract The development of synthetic methodology allowing for a strategic incorporation of fluorine into target compounds is in a high demand in many areas of the chemical and pharmaceutical industries. In this regard, application of fluorinated chiral sulfinimine reagents, in particularly, N-tert-butylsulfinyl-3,3,3-trifluoroacetaldimine, is one of the most general and practical approaches for preparation of compounds containing pharmacophoric fluoro-amino-keto/hydroxy moieties. This article provides a timely and comprehensive overview of the recent synthetic applications of fluorinated chiral sulfinimine reagents for asymmetric synthesis of fluoro-containing polyfunctional amino-compound…

Chemistry of detrifluoroacetylativelyin situgenerated fluoro-enolates

This review article comprehensively profiles all literature reports (2015-2018) related to the detrifluoroacetylative in situ generation of fluorine-containing enolates and their reactions with electrophilic reagents. The innovative facets of this unconventional methodology and its synthetic generality for the preparation of fluorine-containing compounds of high medicinal value are highlighted.

A metal-free and regioselective approach to (Z)-β-fluorovinyl sulfones and their chemoselective hydrogenation to β-fluoroalkyl sulfones

Abstract A highly regioselective, metal-free hydrofluorination reaction of alkynyl sulfones was developed using TBAF—one of the cheapest and most commonly available fluoride sources. In addition, the reactivity of the resulting β-fluorovinyl sulfones was studied, focusing on their selective hydrogenation reaction. Both β-fluorovinyl sulfones and their hydrogenation products β-fluoroalkyl sulfones may find applications in medicinal and agrochemical sciences.

ChemInform Abstract: An Approach to 2,4-Substituted Pyrazolo[1,5-a]pyridines and Pyrazolo[1,5-a]azepines by Ring-Closing Metathesis.

Based on the title approach, the diastereoselective synthesis of potential peptidomimetics [(XI) and (XIV)] is described.

Copper-catalyzed regioselective synthesis of (E)-β-fluorovinyl sulfones

Organofluorine compounds are finding increasing application in a variety of fields such as pharmaceutical, agrochemical, and material sciences. However, given the scarcity of fluorine-containing natural products, advancement in this area depends almost entirely on the development of new synthetic methodologies. In this article, we present the synthesis of a series of previously undescribed (E)-&beta

The Ruthenium‐Catalyzed Domino Cross Enyne Metathesis/Ring‐Closing Metathesis in the Synthesis of Enantioenriched Nitrogen‐Containing Heterocycles

Fluorinated Pyrazoles and Indazoles

The synthesis of fluorine containing pyrazoles has been boosted in the past decades due to the interesting properties that confer these building blocks in pharmaceutical and agricultural active ingredients. There are two main methods for the synthesis of fluorine-containing organic compounds, namely, the direct replacement of an atom or functional group such as diazo, hydroxyl, halogen or hydrogen by fluorine, and the modification of fluorine-containing building blocks. In the case of fluorinated pyrazoles the latter approach is the most commonly applied. This chapter deals primarily with the pivotal procedures that allow the preparation of fluoro- and fluoroalkyl- pyrazoles. Their benzocon…

ChemInform Abstract: Asymmetric Synthesis of Monofluorinated 1-Amino-1,2-dihydronaphthalene and 1,3-Amino Alcohol Derivatives.

Enantioenriched 1-amino-4-fluoro-1,2-dihydronaphthalene derivatives are accessed via two complementary synthetic strategies. The careful optimization of the reaction conditions required for the elimination step in one route has allowed both the identification of an anchimerically assisted reaction pathway and, more importantly, access to a divergent reaction pathway toward fluorinated 1,3-amino alcohols from a common intermediate just by adjusting the number of equivalents of base used.

Synthesis of Fluorinated and Nonfluorinated Tebufenpyrad Analogues for the Study of Anti-angiogenesis MOA

In this contribution we report the synthesis of fluorinated and nonfluorinated tebufenpyrad analogues to explore potential druglike properties through the phenotypic screening as part of the Lilly Open Innovation Drug Discovery (OIDD) program.

Improved Regioselectivity in Pyrazole Formation through the Use of Fluorinated Alcohols as Solvents: Synthesis and Biological Activity of Fluorinated Tebufenpyrad Analogs

The preparation of N-methylpyrazoles is usually accomplished through reaction of a suitable 1,3-diketone with methylhydrazine in ethanol as the solvent. This strategy, however, leads to the formation of regioisomeric mixtures of N-methylpyrazoles, which sometimes are difficult to separate. We have determined that the use of fluorinated alcohols such as 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as solvents dramatically increases the regioselectivity in the pyrazole formation, and we have used this modification in a straightforward synthesis of fluorinated analogs of Tebufenpyrad with acaricide activity. Fil: Fustero, Santos. Universidad de Valencia; España Fil…

Asymmetric Synthesis of Monofluorinated 1-Amino-1,2-dihydronaphthalene and 1,3-Amino Alcohol Derivatives.

Enantioenriched 1-amino-4-fluoro-1,2-dihydronaphthalene derivatives are accessed via two complementary synthetic strategies. The careful optimization of the reaction conditions required for the elimination step in one route has allowed both the identification of an anchimerically assisted reaction pathway and, more importantly, access to a divergent reaction pathway toward fluorinated 1,3-amino alcohols from a common intermediate just by adjusting the number of equivalents of base used.

Synthesis of new fluorinated Tebufenpyrad analogs with acaricidal activity through regioselective pyrazole formation.

In previous studies, our group has shown that the use of fluorinated alcohols such as trifluoroethanol (TFE) and hexafluoroisopropanol (HFIP) as solvents dramatically increases the regioselectivity in the pyrazole formation from 1,3-diketone with methylhydrazine. We have now applied this synthetic method to the preparation of new fluorinated pyrazoles, which have then been used as synthetic intermediates in the preparation of fluorinated analogs of Tebufenpyrad, a commercial acaricide. These compounds display a strong acaricidal activity that is either comparable to or better than that of the commercial compound.

Vinyl Fluorides: Competent Olefinic Counterparts in the Intramolecular Pauson–Khand Reaction

Despite the great advances achieved in the Pauson-Khand reaction and the ever-increasing demand for fluorinated compounds, the use of vinyl fluorides as olefinic counterparts in the above-mentioned transformation had been completely overlooked. Herein, we describe, for the first time, the intramolecular Pauson-Khand reaction of enynes containing a vinyl fluoride moiety.

ChemInform Abstract: Asymmetric Synthesis of Fluorinated Isoindolinones Through Palladium-Catalyzed Carbonylative Amination of Enantioenriched Benzylic Carbamates.

The asymmetric synthesis of fluorinated isoindolinones has been achieved by a palladium-catalyzed aminocarbonylation reaction of the corresponding α-fluoroalkyl o-iodobenzylamines. A base-mediated anti β-hydride elimination process was suggested to explain the partial erosion of the optical purity observed in some cases. This mechanistic rationale enabled the minimization of this partial racemization by fine-tuning the pKa of the base.

Asymmetric Synthesis of Fluorinated Monoterpenic Alkaloid Derivatives from Chiral Fluoroalkyl Aldimines via the Pauson‐Khand Reaction

Asymmetric Allylation/RCM-Mediated Synthesis of Fluorinated Benzo-Fused Bicyclic Homoallylic Amines As Dihydronaphthalene Derivatives

Enantiomerically enriched fluorinated benzo-fused bicyclic homoallylic amities have been synthesized through an asymmetric allylation/ring closing metathesis (RCM) sequence. This sequence has been carried out using alpha-trifluoromethylstyrene derivatives as key intermediates, synthesized by microwave radiation. The great deactivating effect exerted by such substituents has been brought to light by a comparative study.

Asymmetric Synthesis of Fluorinated Isoindolinones through Palladium-Catalyzed Carbonylative Amination of Enantioenriched Benzylic Carbamates

The asymmetric synthesis of fluorinated isoindolinones has been achieved by a palladium-catalyzed aminocarbonylation reaction of the corresponding -fluoroalkyl o-iodobenzylamines. A base-mediated anti -hydride elimination process was suggested to explain the partial erosion of the optical purity observed in some cases. This mechanistic rationale enabled the minimization of this partial racemization by fine-tuning the pK(a) of the base.

Asymmetric Vinylogous Mukaiyama‐Mannich Reactions of Heterocyclic Siloxy Dienes with Ellman's Fluorinated Aldimines

Metal-Free and User-Friendly Regioselective Hydroxyfluorination of Olefins

A simple, user-friendly, metal-free protocol for the regioselective anti-Markovnikov hydrofluorination of olefins using readily available and inexpensive reagents has been developed. This new approach displays a broader scope than previously reported methodologies and has been applied to the late-stage fluorination of a complex molecule, giving rise to a fluorosteroid derivative. The stereochemistry of the process has also been studied in some detail.

New Fluorinated 1,3-Vinylogous Amidines as Versatile Intermediates: Synthesis of Fluorinated Pyrimidin-2(1H)-ones.

The condensation of the azaenolates derived from readily available ketimines with fluorinated nitriles offers an efficient and straightforward entry to new fluorinated 1,3-vinylogous amidines. These versatile compounds, in turn, react with triphosgene to yield new fluorinated pyrimidin-2(1H)-ones in high yields.

Activation of Neurogenesis in Multipotent Stem Cells Cultured In Vitro and in the Spinal Cord Tissue After Severe Injury by Inhibition of Glycogen Synthase Kinase-3

AbstractThe inhibition of glycogen synthase kinase-3 (GSK-3) can induce neurogenesis, and the associated activation of Wnt/β-catenin signaling via GSK-3 inhibition may represent a means to promote motor function recovery following spinal cord injury (SCI) via increased astrocyte migration, reduced astrocyte apoptosis, and enhanced axonal growth. Herein, we assessed the effects of GSK-3 inhibition in vitro on the neurogenesis of ependymal stem/progenitor cells (epSPCs) resident in the mouse spinal cord and of human embryonic stem cell–derived neural progenitors (hESC-NPs) and human-induced pluripotent stem cell–derived neural progenitors (hiPSC-NPs) and in vivo on spinal cord tissue regenera…

Recent advances in the synthesis of functionalised monofluorinated compounds.

Over the past few years, we have tackled the synthesis of interesting monofluorinated organic molecules, such as: dihydronaphthalene derivatives, β-fluoro sulfones and related carbonyl compounds, fluorohydrins and allylic alcohols. Overall, a wide range of modern synthetic techniques are covered in this feature article including transition-metal, photo- and organocatalysis, nucleophilic and electrophilic fluorinations, chiral auxiliaries and enantioselective catalysis.

An efficient synthesis of uracil derivatives from 2-alkyl-Δ2-oxazolines and nitriles

An efficient and convenient synthesis of new fluorinated and non-fluorinated uracils is described herein. The condensation of nitriles with enolates generated from 2-alkyl-Δ 2 -oxazolines (I) affords fluorinated β-enamino acid derivatives, which react with triphosgene to give an isomeric mixture of oxazolopyrimidinones. These can then be easily transformed into a single C-6 pyrimidindione derivative through reaction with a suitable nucleophile.

Biorelevant fluorine-containing N-heterocycles

Abstract Over the course of many decades, life sciences have gained an insight into the structure–activity relationship of biologically active molecules, thereby allowing for a deeper understanding of how such molecules can be modified to produce the desired effect within a living organism. The introduction of either a nitrogen-containing heterocycle or a fluorine-containing unit are commonly used strategies in the pharmaceutical and agrochemical industries to fine-tune the activity, toxicity, and metabolic stability, among other properties, of their respective products. Herein, an overview of the latest fluorine containing N-heterocyclic molecules of significant biological importance, eith…

An Approach to 2,4-Substituted Pyrazolo[1,5-a]pyridines and Pyrazolo[1,5-a]azepines by Ring-Closing Metathesis

The ring-closing metathesis (RCM) reactions of dienylpyrazoles have been employed in the synthesis of pyrazolo[1,5-a]pyridine and pyrazolo[1,5-a]azepine derivatives. Based on this approach, the diastereoselective synthesis of potential peptidomimetics containing four amino acid residues with the second (i+1) and third (i+2) fragments having been substituted by bicyclic frameworks is described.

Chemical Aspects of Human and Environmental Overload with Fluorine

Over the last 100-120 years, due to the ever-increasing importance of fluorine-containing compounds in modern technology and daily life, the explosive development of the fluorochemical industry led to an enormous increase of emission of fluoride ions into the biosphere. This made it more and more important to understand the biological activities, metabolism, degradation, and possible environmental hazards of such substances. This comprehensive and critical review focuses on the effects of fluoride ions and organofluorine compounds (mainly pharmaceuticals and agrochemicals) on human health and the environment. To give a better overview, various connected topics are also discussed: reasons an…

The Fluoro-Pauson-Khand Reaction in the Synthesis of Enantioenriched Nitrogenated Bicycles Bearing a Quaternary C-F Stereogenic Center

The authors are grateful to the Spanish MICINN and the AEI (CTQ2017-84249-P) for financial support, the SCSIE (Universitat de Valencia) for access to instrumental facilities, and M. ̀ R. Pedrosa (Universidad de Burgos) for providing us with MoO2Cl2. The technical and human support provided by SGIker (UPV/EHU, MINECO, GV/DJ, ERDF, and ESF) is also gratefully acknowledged. P.B. thanks the Spanish Ministry of Economy for a Ramon y Cajal contract (RyC-2016-20951). ́ The authors are also grateful to Jose Cabeza for assistance in the synthesis of certain starting materials.

CCDC 1972570: Experimental Crystal Structure Determination

Related Article: Alberto Llobat, Jorge Escorihuela, Daniel M. Sedgwick, Miriam Rodenes, Raquel Román, Vadim A. Soloshonok, Jianlin Han, Mercedes Medio-Simón, Santos Fustero|2020|Eur.J.Org.Chem.|2020|4193|doi:10.1002/ejoc.202000598

CCDC 841484: Experimental Crystal Structure Determination

Related Article: Santos Fustero, Raquel Román, Amparo Asensio, Miguel A. Maestro, José L. Aceña, Antonio Simón-Fuentes|2013|Eur.J.Org.Chem.|2013|7164|doi:10.1002/ejoc.201300901

CCDC 1908613: Experimental Crystal Structure Determination

Related Article: Santos Fustero, Miriam Rodenes, Raquel Román, Daniel M. Sedgwick, José Enrique Aguado, Vadim A. Soloshonok, Jianlin Han, Haibo Mei, Mercedes Medio‐Simon, Pablo Barrio|2019|Adv.Synth.Catal.|361|3860|doi:10.1002/adsc.201900464

CCDC 1937096: Experimental Crystal Structure Determination

Related Article: Alberto Llobat, Raquel Román, Natalia Mateu, Daniel M. Sedgwick, Pablo Barrio, Mercedes Medio-Simón, Santos Fustero|2019|Org.Lett.|21|7294|doi:10.1021/acs.orglett.9b02557

CCDC 941485: Experimental Crystal Structure Determination

Related Article: Santos Fustero, Raquel Román, Amparo Asensio, Miguel A. Maestro, José L. Aceña, Antonio Simón-Fuentes|2013|Eur.J.Org.Chem.|2013|7164|doi:10.1002/ejoc.201300901

CCDC 1954729: Experimental Crystal Structure Determination

Related Article: Alberto Llobat, Daniel M. Sedgwick, Albert Cabré, Raquel Román, Natalia Mateu, Jorge Escorihuela, Mercedes Medio‐Simón, Vadim Soloshonok, Jianlin Han, Antoni Riera, Santos Fustero|2020|Adv.Synth.Catal.|362 |1378 |doi:10.1002/adsc.201901504

CCDC 1908615: Experimental Crystal Structure Determination

Related Article: Santos Fustero, Miriam Rodenes, Raquel Román, Daniel M. Sedgwick, José Enrique Aguado, Vadim A. Soloshonok, Jianlin Han, Haibo Mei, Mercedes Medio‐Simon, Pablo Barrio|2019|Adv.Synth.Catal.|361|3860|doi:10.1002/adsc.201900464

CCDC 1908614: Experimental Crystal Structure Determination

Related Article: Santos Fustero, Miriam Rodenes, Raquel Román, Daniel M. Sedgwick, José Enrique Aguado, Vadim A. Soloshonok, Jianlin Han, Haibo Mei, Mercedes Medio‐Simon, Pablo Barrio|2019|Adv.Synth.Catal.|361|3860|doi:10.1002/adsc.201900464