Photoredox-catalysed acyloxydifluoromethylation of styrenes with difluoromethyltriphenylphosphonium bromide Shen Zhang 1 , Xacobe Cambeiro 2 1 Queen Mary University of London, China, 2 University of Greenwich The difluoromethyl (CF 2 H) substituent offers great potential for the modulation of biological, physical and chemical properties in new agrochemicals, pharmaceuticals and organic functional materials candidates. 1 Therefore, significant attention has been paid to the preparation of difluoromethyl compounds, using a variety of fluorinating agents such as SF 4 , HF, DAST and BAST. However, these F sources are toxic and unstable, and the reaction conditions are also forcing. More recently, reagents leading to the in situ formation of difluoromethyl radical 2 (e.g. HCF 2 I, Zn(SO 2 CF 2 H) 2 ) or difluorocarbene 2a (e.g. HCF 2 SO 2 Cl, HCF 2 SO 2 Na) have emerged as powerful strategies. However, the use of these compounds poses practical challenges associated to their preparation, handling and storage and disposal. Very recently, the readily prepared difluoromethyltriphenylphosphonium bromide has been reported as an efficient difluoromethylating reagent under photocatalytic conditions. 1a Here we present our investigations on the photocatalytic acyloxydifluoromethylation of alkenes using difluoromethyltriphenylphosphonium bromide and an Ir photoredox catalyst.
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