Highly enantioselective [3+2] coupling of indoles with quinone monoimines promoted by a chiral phosphoric acid.

Highly enantioselective [3+2] coupling of 3-substituted indoles with quinone monoimines promoted by a chiral phosphoric acid has been reported. A large variety of benzofuroindolines were prepared in moderate to good yields (up to 98%) with generally excellent enantioselectivities (up to 99 % ee).