Reaction of 2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithiethane with N-vinyl compounds

Abstract

The reaction of hexafluorothioacetone dimer (2,2,4,4- tetrakis(trifluoromethyl)-1,3-dithiethane, 1) with vinylamides leads to the rapid formation of [2 + 2] cycloadducts: 4-amino-2,2-bis(trifluoromethyl) thietanes. The reaction proceeds in polar solvents (DMF, DMSO) in the absence of a catalyst at elevated temperature producing the corresponding cycloadducts in 47-86% yield. The reaction of N-vinylimidazole unexpectedly led to the formation of the corresponding 1-(hexafluoroisopropyl)-3-vinyl-1,3-dihydro-2Himidazole-2- thione (5). The structure of this compound, along with the structures of two new thietanes was confirmed by single crystal X-ray diffraction. © 2013 Petrov and Marshall.