Silver-Mediated Intramolecular Friedel–Crafts-Type Cyclizations of 2-Benzyloxy-3-bromoindolines: Synthesis of Isochromeno[3,4-b] indolines and 3-Arylindoles
We disclose a silver-mediated intramolecular Friedel–Crafts-type cyclization of 2-benzyloxy-3-bromoindolines to afford an untapped family of isochromeno[3,4-b]indolines and 3-arylindoles, in which deformylative arylation of 2-(4-methoxybenzyloxy)-3-bromoindolines is reported for the first time. The isochromeno[3,4-b]indolines can be readily transformed into other heterocyclic moieties.