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

Functionalized dialdehydes are considered important substrates, which may be transformed into various substituted heterocycles, 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

Homoallylic o-halobenzylamines: asymmetric diversity-oriented synthesis of benzo-fused cyclic amines

The presence of a halogen atom in the proximity of a homoallylic amine, obtained by asymmetric addition of allylzinc bromide to the corresponding tert-butyl sulfinimine, makes them versatile building blocks suitable to participate in several palladium-catalyzed processes, such as the intramolecular Heck reaction or the Sonogashira cross-coupling. The thus obtained orthoalkynyl derivatives display two unsaturated functional groups which may be further modified by means of the intramolecular Pauson–Khand reaction or the ring-closing enyne metathesis. In this way, a variety of benzo-fused amines can be obtained in 2–3 steps from readily available starting materials

Asymmetric Michael Addition in Synthesis of β-Substituted GABA Derivatives

γ-Aminobutyric acid (GABA) represents one of the most prolific structural units widely used in the design of modern pharmaceuticals. For example, β-substituted GABA derivatives are found in numerous neurological drugs, such as baclofen, phenibut, tolibut, pregabalin, phenylpiracetam, brivaracetam, and rolipram, to mention just a few. In this review, we critically discuss the literature data reported on the preparation of substituted GABA derivatives using the Michael addition reaction as a key synthetic transformation. Special attention is paid to asymmetric methods featuring synthetically useful stereochemical outcomes and operational simplicity.This research was funded by the National Natural Science Foundation of China (No. 21761132021), and IKERBASQUE, Basque Foundation for Science. The financial support from the University of the Basque Country UPV/EHU (UFIQOSYC11/22), Basque Government (GVgrant IT1236-19), and Ministerio de Ciencia e Innovación (grant PID2019-109633GBC21) for. A.L. are also acknowledged

An efficient synthesis of new fluorinated uracil derivatives

A series of potentially biologically active fluorinated uracil derivatives has been prepared in three steps from oxazolines and fluorinated nitriles with good chemical yields.Fustero Lardies, Santos, [email protected] ; Sanz Cervera, Juan Francisco, [email protected] ; Asensio Martinez, Amparo, [email protected]

A de novo Synthetic Route to 1,2,3,4-Tetrahydroisoquinoline Derivatives

A novel synthetic approach was developed for the construction of the 1,2,3,4-tetrahydroisoquinoline framework possessing varied functions. The synthetic strategy was based on oxidative ring opening of some indene derivatives through their C=C bond, followed by double reductive amination of the dicarbonyl intermediates with various primary alkyl- or fluoroalkylamines

Recent developments and applications of the chiral Brønsted acid catalyzed allylboration of carbonyl compounds

The 50-year-old allylboration reaction has seen dramatic developments since the dawn of the new century after the first catalytic asymmetric versions came into play. In the past decade alone, several methodologies capable of achieving the desired homoallylic alcohols in over 90% e.e. have been developed. This review focuses on the chiral Brønsted acid-catalyzed allylboration reaction—covering everything from the very first examples and precedents to modern day variations and applications—and includes the following sections: 1. Introduction 2. Early developments 3. Synthetic applications 4. Variants 5. Computational contributionWe thank the Spanish MINECO (CTQ2013-43310) and Generalitat Valenciana (PROMETEOII/2014/073) for their financial support. D. M. S. is grateful to the Spanish Government for an FPU fellowship. We are grateful to Girton College, Cambridge (Research Fellowship to M.N.G.) for financial support

Ring-opening metathesis of some strained bicyclic systems; stereocontrolled access to diolefinated saturated heterocycles with multiple stereogenic centers

Ring-opening metathesis (ROM) of various unsaturated, constrained bicyclic ring systems has been investigated with the use of commercial ruthenium-based catalysts. Starting from various cyclodienes, the corresponding derived bicyclic lactone, lactam, and isoxazoline derivatives were submitted to ROM under ethenolysis. These functionalized, strained bicyclic systems afforded novel highly-functionalized diolefinated heterocyclic scaffolds in ROM reactions with stereocontrol, through the conservation of the configuration of the stereogenic centers of the starting compounds