One-Pot Unsymmetrical {[4 + 2] and [4 + 2]} Double Annulations of o/ o′-C-H Bonds of Arenes: Access to Unusual Pyranoisoquinolines

Abstract

With the aid of a transformable sulfoximine directing group, unprecedented one-pot unsymmetrical double annulations {[4 + 2] and [4 + 2]} of hetero(arenes) with alkynes are revealed under Ru(II) catalysis. Functionalization of both ortho-C-H bonds of (hetero)arene is reflected in the building of unusual 6,6-fused pyranoisoquinoline skeletons. Construction of four [(C-C)-(C-N) and (C-C)-(C-O)] bonds occurs in one step under single catalytic conditions. The challenging unsymmetrical double annulations of both o-C-H bonds of arenes with two distinct alkynes is effectively demonstrated. Control experiments and deuterium scrambling findings are shown.