Rhodium-Catalyzed Stereoselective Formation of Z-Enamines from Allylaziridines

摘要

Enols,metal enolates,and enamines are the most important carbon nucleophiles in both biological and chemical synthesis.Many useful reactions owe their efficiency to selective formation of E or Z metal enolates(Figure 1).In contrast,the chemistry of enamines is limited to reactions of the E-isomers.The reason is simple:a classical condensation between an amine and a carbonyl compound is an equilibrium process that affords the thermodynami-cally more stable E-isomer.Transition-metal-catalyzed approaches to enamines include metal-catalyzed isomerization of N-ally-lamines,amination of alkenyl halides,hydroamination of alkynes,and oxidative amination of olefins.