An efficient, simple, and practical method has been developed
to regioselectively synthesize (E)-stilbenes
and (E,E)-1,4-diphenylbuta-1,3-diene
in good to excellent yields in the presence of boron trifluoride-diethyl
ether complex as a catalyst in a short reaction (30-60
s) at room temperature.
boron trifluoride-diethyl ether complex - (E)-stilbenes - (E,E)-1,4-diphenylbuta-1,3-diene - ketones - regioselectivity