One-pot synthesis of 3-trifluoromethylbenzo[<i>b</i>][1,4]oxazines from CF₃-imidoyl sulfoxonium ylides with 2-bromophenols

Abstract

Herein, a method to access 3-trifluoromethyl-1,4-benzoxazines from CF₃-imidoyl sulfoxonium ylides and 2-bromophenols has been demonstrated. This synthetic protocol proceeds <i>via</i> a one-pot two-step sequence that includes the lithium-bromide-promoted O-H insertion of sulfoxonium ylides and annulation, and has the merits of broad substrate scope, excellent functional tolerance and operational simplicity, which provides an alternative means of obtaining CF₃-substituted heterocycles.