Reaction of triphenyl(phenylethynyl)phosphonium bromide with α-aminoethers, dipiperidinomethane, and secondary amines

The reactions of triphenyl(phenylethynyl)phosphonium bromide with (alpha-aminoethers lead to formation of triphenyl(2-amino-2-phenylvinyl)phosphonium bromides. In the case of acyclic aminoethers, this reaction is accompanied by the formation of the corresponding amine hydrobromide and triphenylphosphine oxide by a scheme analogous to that of alkaline hydrolysis of phosphonium salts and involving attack of the amine on the phosphorus atom. The reaction of the same salt with diethyl- or dipropylamine affords hydrobromides of the latter, while with piperidine, together with salts, its adduct by the triple bond is formed. Piperidinomethane with the same salt forms triphenylphosphonium (2-phenyl-2-piperidinovinyl)phosphonium bromide.