Gallium(III) halide promoted synthesis of 1,3,5-triaryl1,5-dihalo-1,4-pentadienes

Aryl substituted alkynes undergo smooth coupling with aldehydes in the presence of gallium(III) halides under extremely mild conditions to afford the corresponding 1,3,5-triaryl-1,5-dihalo-1,4-pentadienes in good yields with E,Z-selectivity. Similarly 1,3,5-triaryl-1,5-dihalo-1,4-pentadienes are also obtained with niobium(V) chloride. (C) 2004 Elsevier Ltd. All rights reserved.