Synthesis of Novel 2-Trifluoromethyl-1-methylene-3-phenylindene Derivatives via Carbocyclization Reaction of 2-Trifluoromethyl-1,1-diphenyl-1,3-enynes.

Abstract Trifluoromethylated enynyl sulfones 3 were reacted with PhLi at −78 °C for 2–4 h to give 2-trifluoromethyl-1,1-diphenyl-1,3-enynes 6 in good yields. Carbocyclization reaction of 6 with 10 mol% of Pd(OAc) 2 in cosolvent of CF 3 COOH and MC (4:1) at room temperature for 1 h afforded 2-trifluoromethyl-1-methylene-3-phenylindene derivatives 7 in good yields.