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

Abstract

Abstract 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.