Asymmetric C3-allenylation of carbazoles with α-indolyl propargylic alcohols

Abstract

A chiral phosphoric acid-catalyzed asymmetric mono- and double-allenylation of carbazoles with α-indolyl propargylic alcohols was realized. This highly efficient protocol produces diverse chiral tetrasubstituted allenes in excellent yields with remarkable chemo-, regio- and enantioselectivities under mild conditions. The practicality of this efficient method is further demonstrated by the good anticancer activities of the obtained chiral allenylationalized carbazole derivatives.