Synthesis of 3-SCF<sub>2</sub>H-/3-SCF<sub>3</sub>-chromones via Interrupted Pummerer Reaction/Intramolecular Cyclization Mediated by Difluoromethyl or Trifluoromethyl Sulfoxide and Tf<sub>2</sub>O.
Xuemin LiYue LiJingyue YangHaofeng ShiZhenkang AiChi HanJiaxin HeYunfei DuPublished in: Organic letters (2022)
The reaction of alkynyl aryl ketones bearing an <i>o</i>-methoxy group with difluoromethyl sulfoxide in the presence of Tf<sub>2</sub>O was found to conveniently afford the corresponding 3-SCF<sub>2</sub>H-substituted chromones. The combining use of difluoromethyl sulfoxide/Tf<sub>2</sub>O could represent the first reagents system that can introduce the biologically important SCF<sub>2</sub>H moiety under base-free conditions via an interrupted Pummerer reaction. The same protocol could also be applied to the synthesis of 3-SCF<sub>3</sub>-substituted chromones by replacing difluoromethyl sulfoxide with trifluoromethyl sulfoxide and CH<sub>3</sub>CN with toluene.