Stabilization of phosphobetaines that form in the reaction of trialkylphosphines with methoxyallene

Article abstract of DOI:10.1007/BF02496021

Reactions of tripropyl- and tributylphosphines with methoxyallene were studied. In the case of tripropylphosphine, a mixture of tripropylphosphine oxide and tripropyl-1-formylethylidenephosphorane (the latter in equilibrium with its O-betaine) was obtained. The reaction with tributylphosphine yields, along with tributylphosphine oxide, two homologous ylides, namely, tributyl-1-formylethylidene- and tributyl-1-formylpropylidene-phosphoranes, which are also in equilibria with their O-betaines. A possible scheme of formation of these ylides is discussed.