One-Step Synthesis of 1,3-Diene Aminophosphonium Salts Based on Buta-1,3-diene-1,4-diylbis(triphenylphosphonium Iodide)

摘要

Recently we have reported that buta-1,3-diene-1,4-diylbis(triphenylphosphonium dichloride) undergoes Hofmann elimination at the action of alkaline agents at room temperature to form intermediate monophos-phonium salt with a but-1-en-3-ynyl group. The latter undergoes anionotropic α-phenyl migration. Heating the salt in a sealed tube at 100°C in the presence of triethylamine affords the Hofmann elimination product, triphenylphosphine, and a large amount of resin, which is likely the result of condensation of the second product of the elimination, the triphenyl-β-ethynylvinylphosphonium chloride [1].