Regioselective Carbozincation and Further Functionalization of Allenamides Catalyzed by an N‐Heterocyclic Carbene (NHC)‐Copper Complex

Abstract An efficient protocol for the carbozincation of allenamides with dialkylzinc reagents catalyzed by an NHC−Cu complex has been developed. This protocol could provide alkenylzinc species introducing the alkyl group to γ‐position and the zinc component to β‐position of the allenamides in a regio‐ and stereoselective manner. The resulting alkenylzinc species can undergo further C−C bond‐forming reactions, such as allylation, arylation, and benzoylation, affording a variety of β,β‐disubstituted enamides with well‐controlled configurations of the two substituents. Moreover, the chiral allenamide synthesized via this method can be converted to a chiral aminocyclopropane derivative. In view of the high regio‐ and stereoselectivity and the convenient one‐pot procedure, this sequential transformation protocol offers a potentially useful method for synthesizing multi‐substituted enamides, which are important compounds in synthetic organic chemistry.