Preparation of 2-(t-butyl)dimethylsilyl-3,3-difluoropropenones via acylation reactions of 1-(t-butyl)dimethylsilyl-2,2-difluoroethenylstannane

Stannylation reaction of 1-(t-butyl)dimethylsilyl-2,2-difluoroethenyl p-toluenesulfonate 1b with hexabutylbistin in the presence of 3 mol% Pd2(dba)3, 6 mol% XPhos and 30 equiv LiBr in THF at reflux temperature for 8 h provided the corresponding 1-(t-butyl)dimethylsilyl-2,2-difluoroethenylstannane 2b in 70% yield. The acylation reaction of 2b with a variety of acyl chlorides in the presence of 5 mol% Pd(PPh3)4 and 10 mol% CuI in THF at reflux temperature for 2 h afforded the 2-(t-butyl)dimethylsilyl-3,3-difluoropropenones 3b-3m in 45-86% yields.