Electrophilic substitution at phosphorus: reactions of diphenylphosphinyl systems with carbonyl compounds

Abstract

Methods of making adducts of diphenylphosphine oxide include the addition of its anion, either as a Grignard reagent or as the sodium salt, to carbonyl compounds. With acetone, the Grignard method gave a substantial yield of a phorone (2,6-dimethylhepta-2,5-dien-4-one) bis-adduct, and with enones addition occurred either to the carbonyl group or to the double bond. A new reaction is described in which a nucleophilic Ph₂PO group is released, by the debenzylation and decarboxylation of benzyl diphenylphosphinylformate, to react with carbonyl compounds or iodine. The debenzylation can be separated kinetically from the rest of the reaction.