Palladium-Catalyzed Cascade C-H Functionalization/Asymmetric Allylation Reaction of Aryl α-Diazoamides and Allenes: Lewis Acid Makes a Difference.

ABSTRACT

A Pd-catalyzed cascade C-H functionalization/asymmetric allylation reaction with aryl α-diazoamides and allenes has been developed. The reaction provides an efficient approach to construct chiral 3,3-disubstituted oxindole derivatives in high levels of yield and enantioselectivity (up to 93 % ee). Notably, the chromium complex works as Lewis acid to facilitate the formation of palladium carbene and to enhance acidity of carboxylic acid, allowing for higher stereochemical control and efficiency.