The reaction of styrenes with triphenylphosphine in the presence of acid gave the corresponding 1-arylethylphosphonium salts in 76–82% yields. Indene also reacted with triphenylphosphine and tetrafluoroboric acid to afford 1-indanyltriphenylphosphonium tetrafluoroborate in 72% yield.
[Von Doering; Benkhoff, Johannes; Carleton, Peter Smart; Pagnotta, Marco Journal of the American Chemical Society, 1997 , vol. 119, # 45 p. 10947 - 10955]
