Asymmetric Synthesis of Chiral Organoselenium Compounds

Abstract

Chiral organoselenium compounds can be attained from three types of asymmetric synthesis. Chiral substratecontrolled methods, chiral auxiliary-controlled methods, and chiral catalyst-controlled methods toward optically active organoselenium derivatives were illustrated. The strategy and classification of methods underlying all asymmetric synthesis therefore involve enantiomerically pure compounds to influence the stereochemical outcome of the reactions. In this review, the advances in asymmetric synthesis of some important classes of chiral organoselenium compounds were described. A. INTRODUCTIONThe asymmetric synthesis of optically active organoselenium compounds constitutes engaging fundamental problems in both scientific research and drug discovery [1]. Over past several years, chiral organoselenium compounds have received a new impetus in the preparations, developments, and asymmetric transformations. The development of stereoselective reactions to form C-Se, Se-Se, Se-O, Sehalogen, Se-N bonds has witnessed the burgeoning levels of diversity, efficiency and applicability [2]. Different chiral selenoorganic functional groups and reagents could be easily synthesized in various means. Optically active diselenides,arylseleno alcohols, -oxo--seleno esters, oxaselenazoles, selenoxides, seleninamides and selenonium ylides were obtained and utilized for some facile transformations, in which these chiral motifs play the critical roles in controlling both the course of the reaction and the stereoselectivity for the specific structural and electronic features [3]. In this review, the recent progress of synthetic methods for some important classes of chiral organoselenium compounds are described. We illustrate three types of asymmetric synthesis according to how the enantiomerically pure compound is used, excluding those processes that involve the derivatization of a reagent without creating any new stereogenic element. The known methods which have been used in asymmetric synthesis of chiral organoselenium compounds are classified into three types:(i) chiral substrate-controlled methods;(ii) chiral auxiliary-controlled methods; (iii) chiral catalyst-controlled methods. B. CHIRAL SUBSTRATE-CONTROLLED METHODSThe chiral substrate-controlled methods may be represented as Equation 1, the influence of an adjacent stereogenic group (X*) involves the formation of a new

Enantioselective Seleno‐Michael Addition Reactions Catalyzed by a Chiral Bifunctional N‐Heterocyclic Carbene with Noncovalent Activation

“…Literature on the synthesis of chiral Se‐containing molecules is surprisingly sparse compared to that of compounds containing other heteroatoms. Most synthetic methods of Se‐bearing stereogenic centers in the literature use non‐Se chiral pool materials that react with nucleophilic selenols or their derivatives through S N 2 displacement [9] . A few catalytic processes have been reported and most of them use electrophilic Se reagents (Scheme 1B).…”

“…Most synthetic methods of Se-bearing stereogenic centers in the literature use non-Se chiral pool materials that react with nucleophilic selenols or their derivatives through S N 2 displacement. [9] A few catalytic processes have been reported and most of them use electrophilic Se reagents (Scheme 1B). Melchiorre reported asymmetric α-selenolation of aldehydes catalyzed by chiral secondary amines.…”

First chemoenzymatic synthesis of organoselenium amines and amides

“…[1][2][3][4][5][6][7][8][9] The constant interest in this area can be devoted to the wide application of selenium to organic synthesis and biological chemistry. For example, we mention that compounds containing a selenium atom have important antioxidant and antiinflammatory activities.…”