One-Pot Synthesis of 2-Arylbenzoxazinones from 2-Arylindoles with (Diacetoxyiodo)benzene as the Sole Oxidant

Abstract

A series of synthetically interesting 2-arylbenzoxazinones was prepared from 2-arylindoles by an efficient oxidative reaction mediated by (diacetoxyiodo)benzene [PhI(OAc)2] and assisted by water. PhI(OAc)2 was used as the sole oxidant and water was a crucial additive. Our preliminary mechanistic investigations suggest that a water-involved, iodine(III)-promoted sequential oxidation of 2-arylindoles, which was terminated by an interesting Grob-type fragmentation of a fused tricyclic precursor, might be the main components of this one-pot transformation.