Preparation of 2,2-difluoro-1-trialkylsilylethenylstannanes and their cross-coupling reactions

Reaction of 2 with bis(tributyltin) in the presence of 3mol% Pd2(dba)3, 6mol% XPhos, and 30equiv of LiBr in wet and air bubbled THF at reflux for 8h afforded the desired products 3 in 73–74% yields. The cross-coupling reaction of 3a with aryl iodides in the presence of 10mol% Pd(PPh3)4 and 10mol% CuI afforded the coupled products 4a–p in 47–90% yields. The coupling reaction of 3b with various alkynyl bromides having aryl-, alkyl, or trialkylsilyl group also afforded the corresponding 1,3-enynes 5a–g in 61–77% yields.