Fragmentation of trifluoromethylated alkenes and acetylenes by N,N-binucleophiles. Synthesis of imidazolines or imidazolidines (oxazolidines) controlled by substituent.

The reaction of beta-halogeno-beta-polyfluoromethylstyrenes with N,N- or N,O-binucleophiles leads to unexpected fragmentation products (imidazolines) or to heterocyclization giving CF(3)-substituted imidazolidines (N,N-) and oxazolidines (N,O-) depending on aryl substituent. The scope and the reaction mechanism are discussed.