Ag-Catalyzed Cyclization-Intermolecular Sulfinyl Group Transfer Cascade Reactions Enabling Enantioselective Synthesis of 4-Sulfinylisoquinolines.

N-Sulfinylimines derived from ortho-alkynylbenzaldehydes were efficiently converted into the corresponding 4-sulfinylisoquinolines in good to excellent yields.  The reaction proceeds via cyclization followed by intermolecular migration of the sulfinyl group from the nitrogen atom to the silver-bound carbon of the resulting cyclized vinylsilver intermediate with the aid of either a counteranion or a nucleophilic species.  Moreover, the Ag-catalyzed reaction in the presence of quinidine acetate as a chiral nucleophilic cocatalyst yielded chiral isoquinolines with high enantioselectivities through a dynamic kinetic asymmetric transformation (DYKAT).