Enantioselective desymmetrization reactions in asymmetric catalysis

Abstract

This review covers the recent developments (since 2015) of enantioselective desymmetrization reactions using metal-catalyzed, organocatalyzed and enzymatic processes of prochiral and meso-compounds. This asymmetric strategy has been applied to a great number of organic compounds such as diarylalkanes, silanes, alcohols, amines and dibenzylmethylamines, as well as unsaturated compounds comprising dienes, diynes and cyclohexenes. The classical desymmetrization of 1,2-, 1,3-diols and other polyols by inter- and intramolecular acylation and alkylation reactions, but also by oxidation methods are important processes. Carbonyl compounds such as cycloalkanones, cyclohexadienones, cyclic and acyclic 1,3-diketones, cyclic 1,4-diketones are desymmetrized and applied to the synthesis of a wide range of natural products. In the case of dicarboxylic acid derivatives, diesters and lactones, anhydrides, diamides and dinitriles are mainly desymmetrized by intra- and intermolecular esterifications and hydrolysis. Small ring carbocycles such as cyclopropanes and cyclopropenes, cyclobutanes and cyclobutenes, and also cyclopentanes and cyclopentenes, cyclohexanes and cyclohexenes are considered. Heterocyclic systems such as small ring oxygen containing epoxides, oxetanes and oxabenzonorbornadienes as well as nitrogen containing aziridines, azetidines, azabenzonorbornadienes and diazanorbornenes are desymmetrized mainly by asymmetric ring opening reactions. The synthetic applications of these desymmetrization methodologies in the total synthesis of natural products and biologically active compounds are highlighted.