Trifluoromethylated cyclopropanes and epoxides from CuI-mediated transformations of alpha-trifluoromethyl-diazophosphonate

摘要

An efficient method for the preparation of alpha-(trifluoromethyl)-cyclopropylphosphonates and alpha-(trifluoromethyl)-l,2-epoxyphosphonates has been developed.The method is based on metal-catalyzed reaction of diethyl l-diazo-2,2,2-trifluoroethylphosphonate (1) with alkenes or carbonyl compounds,respectively.It established an essential advantage of CuI-catalysis over Rh2(OAc)4 in cyclopropanation reactions.An inexpensive copper iodide has also exhibited a good catalytic activity in the synthesis of epoxyphosphonates (3).