Light-Induced Intramolecular Carbene C(sp 3 )-H Insertion of N-Tosylhydrazones; Synthesis of Functionalized Coumarans and Indolines

We report a light-induced intramolecular carbene C(sp3)–H insertion under metal-free conditions using caesium carbonate, which allows access to highly functionalized coumarans and indolines in high yields. This method's versatility is demonstrated by the bis-C–H insertion, and its synthetic applications for various transformations, one-pot synthesis, and precursor of biologically active molecules.