Enantioselective Gold-Catalyzed Synthesis of Heterocyclic Compounds

Abstract

Asymmetric gold-catalyzed syntheses of a diverse range of heterocycles are described herein. This chapter outlines efforts toward the construction of these molecules via intermolecular, intramolecular, and tandem cyclization strategies. Additionally, asymmetric hydrogenation and epoxidation approaches are detailed. These methodologies generally utilize substrates containing soft, unsaturated carbon-carbon bonds, which can easily interact with the carbophilic gold atom(s). Mostly through the use of bis-or monophosphine ligands, modest to excellent yields and enantioselectivities are obtained for a variety of partially and fully saturated heterocycles. Although steric variation of the phosphine catalyst is the most commonly used strategy for enantioinduction, the use of chiral counteranions has proven useful for more challenging transformations. This chapter includes only examples of syntheses where a chiral gold catalyst is used in the direct formation of the heterocycle; examples of pendant functionalization of an existing heterocycle or chirality transfer from enantioenriched substrate to product are not included.

Gold-Catalyzed Synthetic Strategies towards Four-Carbon Ring Systems

“…Therefore, gold catalysts promote chemical transformations unavailable using other metal-derived catalysts or have higher activity and selectivity than less expensive catalysts, thus allowing the reactions to be run at low temperatures and catalyst loadings. Additionally, high regio-and diastereoselective gold-catalyzed processes and the application in asymmetric synthesis have been reported [84][85][86][87][88][89][90][91][92][93][94][95][96][97][98][99].…”