Process for forming a bromomagnesium tetrakis (fluorophenyl) borate

摘要

Bromomagnesium tetrakis(fluorophenyl) borate reactible intermediates can be formed by reacting at least four equivalents of fluorophenyl magnesium bromide with every one equivalent of boron trifluoride in ether solvent using a sufficient amount of heat to drive the reaction to completion. This type of reactible intermediate can then be reacted with a salt containing a suitable cation, such as ammonium, trityl or onium, preferably substituted with phenyl or alkyl, such as lower alkyl, to form the desired combination of weakly coordinating boron anion and activating cation.