Iridium-Catalyzed Enantioselective Alkene Hydroalkylation via a Heteroaryl-Directed Enolization–Decarboxylation Sequence
Changcheng Jing, Wenbin Mao, John F. Bower
Abstract
High Resolution Image Download MS PowerPoint Slide Upon exposure to a cationic Ir(I)-complex modified with the chiral diphosphine DuanPhos, hydroalkylations of styrenes and α-olefins with diverse heteroaryl tert -butyl acetates occur with complete branched selectivity and very high enantioselectivity. The initial adducts undergo acid promoted decarboxylation in situ to provide alkylated heteroarenes possessing defined β-stereocenters. The processes are postulated to proceed via a stereodefined chiral Ir-enolate, which arises upon heteroarene directed enolization of the heteroaryl acetate precursor. The method can be classified as an enantioselective decarboxylative C(sp 3 )–C(sp 3 ) cross-coupling.
Topics & Concepts
ChemistryEnantioselective synthesisIridiumAlkeneDecarboxylationCatalysisKeto–enol tautomerismSequence (biology)StereochemistryCombinatorial chemistryOrganic chemistryBiochemistryAsymmetric Hydrogenation and CatalysisCatalytic C–H Functionalization MethodsAsymmetric Synthesis and Catalysis