Copper-Catalyzed Tandem CC/CO Bond-Forming Reactions of ortho-Halo-β-chlorostyrenes with Ketones: Synthesis of 4-Trifluoromethylbenzoxepines

   A copper-catalyzed cyclization reaction of trifluoromethyl-containing ortho-halo-β-chlorostyrenes with ketones has been developed. Using a combination of copper(I) bromide, 2,2,6,6-tetramethylheptane-3,5-dione and sodium tert-butoxide, a variety of 4-trifluoromethylbenzoxepines was prepared in moderate to good yields by the tandem α-alkenylation of ketones with subsequent O-arylation.

 http://onlinelibrary.wiley.com/doi/10.1002/adsc.201200784/full