Cyclization of ortho-alkynylphenylphosphine P-ylides; dependence on ylide nucleophilicity

Abstract P=CH 2 ylides derived from ortho -alkynylphenylphosphines readily cyclize to give phosphindole derivatives. With a stabilized ylide such as P=CHC(O)Ph, the outcome of the reaction is completely different. The reaction proceeds at high temperature and produces phosphanaphthalenes.