Aldol Reaction of Enol Esters Catalyzed by Cationic Species Paired with Tetrakis(pentafluorophenyl)borate

The crossed aldol reaction of enol esters, which are weak carbon nucleophiles, with aldehydes was effectively carried out under mild conditions by using a catalytic amount of several cationic species paired with tetrakis(pentafluorophenyl)borate.