One-pot synthesis of 3-trifluoromethylbenzo[b][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 in a one-pot two-step sequence including lithium-bromide-promoted O-H insertion of sulfoxonium...

Recent advances in the synthesis of trifluoromethyl-containing heterocyclic compounds via trifluoromethyl building blocks

“…TFISYs offer significant advantages such as easy availability and handling, relative stability and safety, and high reactivity. Thus, they have been favored by numerous scientific working groups [82][83][84][85][86][87][88][89][90][91] in recent years as powerful and promising trifluoromethyl-containing building blocks.…”

Construction of trifluoromethyl-containing heterocycles from trifluoroacetimidoyl chlorides and derivatives

“…The imidoylmethylation Xiong and co-workers described a LiBr-promoted cascade annulation of CF 3 -imidoyl sulfoxonium ylides and 2-bromophenols for the synthesis of 3-trifluoromethyl-1,4-benzoxazines (Scheme 49). 62 The one-pot two-step reaction included a O-H insertion of TFISYs and intramolecular Buchwald-Hartwig reaction to enable the cyclization. Except for the common 2-bromophenols, 2-chlorophenol and 2-bromobenzenethiol also served as the viable substrates in the reaction.…”

Synthesis of Multifunctionalized Thiazolidine‐4‐thiones via [2+2+1] Annulation of Isothiocyanates and CF3‐Imidoyl Sulfoxonium Ylides

“…[7c] Subsequently, Xiong reported a sequence LiBr-promoted OÀ H insertion of TFISYs/palladium-catalyzed annulation reaction for the synthesis of 3-CF 3 -1,4- benzoxazines. [8] Furthermore, Cheng's group achieved the synthesis of 4-CF 3 -2,3-dihydrothiazoles from αenolic dithioesters and TFISYs under catalyst-and additive-free conditions. [9] Several CF 3 -decorated heterocycles were also prepared from TFISYs by Wu's group.…”

“…As our ongoing interest in sulfoxonium ylides chemistry, [6] we have recently synthesized a range of CF 3 ‐imidoyl sulfoxonium ylides (TFISYs), which have demonstrated their versatility as fundamental building blocks for the synthesis of CF 3 ‐containing pyrroles, [7a] pyridines, [7b] and isoquinolinones [7c] . Subsequently, Xiong reported a sequence LiBr‐promoted O−H insertion of TFISYs/palladium‐catalyzed annulation reaction for the synthesis of 3‐CF 3 ‐1,4‐benzoxazines [8] . Furthermore, Cheng's group achieved the synthesis of 4‐CF 3 ‐2,3‐dihydrothiazoles from α ‐enolic dithioesters and TFISYs under catalyst‐ and additive‐free conditions [9] .…”