Synthesis of 3-trifluoroethylfurans by palladium-catalyzed cyclization-isomerization of (Z)-2-alkynyl-3-trifluoromethyl allylic alcohols
Hydroiodonation of trifluoromethyl propargylic alcohols 1 regio- and stereoselectively produce (Z)-2-iodo-3-trifluoromethyl allylic alcohols 2. (Z)-2-Alkynyl-3-trifluoromethyl allylic alcohols 5, available through Pd(PPh3)4-mediated coupling of 2 and terminal alkynes 4, cyclize and subsequently isomerize to 3-trifluoroethylfurans 6 upon catalysis under PdCl2(CH3CN)2 in THF at 5-10 degrees C.
Qing
FL
Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, P. R. China. flq@pub.sioc.ac.cn
Gao
WZ
Ying
J