Bromoaroylmethylidenephosphoranes 3 are reacted with aryl- and hetarylboron
ic acids under Suzuki-Kumada conditions to yield biaryl- and arylhetaryl-ca
rbonylmethylidenephosphoranes 4. The reaction can also be run in a one-step
procedure from (bromoaroylmethyl)triphenylphosphonium bromides 2. 4 are ai
r-stable phosphoranes that undergo Wittig olefination reactions with aldehy
des under benzoic acid catalysis.