Switching the Regioselectivity Access to Pyrroles and Isoquinolines from Ketoxime Acetates and Ynals.

A novel formal [3+2] and [4+2] annulation of ketoxime acetates and ynals for the synthesis of pyrroles and isoquinolines has been developed. By simply switching the catalyst and solvent, the reaction proceeds via two pathways. The reactions are achieved under mild conditions with broad substrate scope and excellent regioselectivity.