Asymmetric N-H insertion of secondary and primary anilines under the catalysis of palladium and chiral guanidine derivatives.

Efficient enantioselective NH insertion reactions of secondary and primary anilines were catalyzed by palladium(0) in combination with chiral guanidine derivatives. A broad range of substituted anilines were tolerated, and the corresponding products were obtained in high yield (up to 99 %) with good enantioselectivity (up to 94 % ee) under mild reaction conditions. The NH insertion mechanism was examined by the study of kinetic isotope effects, control experiments, HRMS, and spectroscopic analysis.