Direct, Enantioselective Iridium-Catalyzed Allylic Amination of Racemic Allylic Alcohols

摘要

Transition-metal-catalyzed asymmetric allylic substitution reactions constitute one of the most convenient approaches for the generation of optically active allylic amines. The best solutions for the enantioselective synthesis of optically active amines from precursor allylic alcohols to date involve the use of primary allylic esters, carbonates, and phosphates as substrates. Substitution of a racemic mixture of secondary allylic alcohols to afford optically active amines has not been achieved to date. This is a shortcoming given that these starting substrates are conveniently accessed by the addition of vinylorganometallic reagents to aldehydes. Herein, we document for the first time the enantioselective displacement of secondary racemic allylic alcohols with sulfamic acid to give directly primary amines in a reaction catalyzed by an optically active Ir-(P,alkene) complex [Eq. (1)].