Recent advances in Rh(III)/Ir(III)-catalyzed C-H functionalization/annulation via carbene migratory insertion

In the past two decades, transition metal-catalyzed C-H functionalization followed by annulations with various coupling partners has received much attention in organic synthesis. In particular, Rh(iii) or Ir(iii) catalyzed regioselective C-H functionalization followed by the cyclization of diverse arenes with metal carbene precursors has become a highly investigated research field in recent years. The purpose of this review is to provide a comprehensive essay on the Rh(iii)/Ir(iii) catalyzed C-H functionalizations/annulations via carbene migratory insertion, focusing on the diverse metal carbene precursors with arenes/alkenes reported so far. The highlighted examples are categorized by nitrogen, oxygen, sulfur-containing heterocycles and carbocyclizations. Further, key mechanistic approaches are also briefly described.