Regioselective Fluorination of 1-(2,2-Dibromovinyl)benzene Derivatives with Wet Tetra-n-butylammonium Fluoride: One-Pot Synthesis of (Z)-1-(2-Bromo-1-fluorovinyl)benzenes.

A direct fluorination of 1-(2,2-dibromovinyl)benzene derivatives using wet tetra-n-butylammonium fluoride (TBAF·3H2O) as either a base or a fluorine source in toluene was accomplished, which provided (Z)-1-(2-bromo-1-fluorovinyl)benzene compounds in up to 81% yields with high regioselectivities. This reaction results strongly depend upon the reaction conditions. The mechanism of this reaction was investigated as well.