Oxazolinyl‐Assisted Ru(II)‐Catalyzed C−H Functionalization Based on Carbene Migratory Insertion: A One‐Pot Three‐Component Cascade Cyclization

A rare, ruthenium‐catalyzed, oxazolinlyl assisted C−H functionalization and three‐component cascade cyclization for the synthesis of isoquinolinones via a metal‐carbene migratory insertion is reported. The transformation is unique since it involves the formation of multiple bonds in one pot via C−H functionalization and ring opening of oxazolines. Detailed mechanistic investigations reveal interesting insights on the mode of transformation, involving reversible C−H activation, migratory insertion of the diazo compound and cascade cyclization as the key step of the transformation.