Synthesis of 2-aryl-1,1-difluoro-1,3-enynes via consecutive cross-coupling reactions of 2,2-difluoro-1-iodoethenyl p-toluenesulfonate

摘要

Alkynylation reaction of 2,2-difluoro-1-iodoethenyl p-toluenesulfonate 1 with alkynyltributylstannanes in the presence of 10 mol% Pd(PPh3)(4) and 10 mol% CuI in THF at reflux temperature for 3 h provided the corresponding 1,1-difluoro-1,3-enynyl tosylates 2 in 65-85% yields. The further arylation reaction of 2 with aryltributylstannanes in the presence of 10 mol% Pd(PPh3)(2)Cl-2 and 3 equiv. of LiBr in THF at reflux temperature for 8 h afforded the coupled products 3 in 32-83% yields. (C) 2014 Elsevier B.V. All rights reserved.