Reactions of triphenyl(3-phenyl-1,2-propadienyl)phosphonium and triphenyl(3-phenyl-2-propynyl)phosphonium bromides with ketones

The authors report on the preparation of the title compounds and their reactions with ketone nucleophiles. They were found to react readily with acetone in the presence of dimethylformamide at the boiling point of the reaction mixture with the formation of adducts. The reactions were found not to proceed in the absence of dimethylformamide. Reactions with acetophenone, on the other hand, occurred both in the presence and absence of the amide, and led to adducts through successive stages of prototropic isomerization and nucleophilic addition. The compounds were determined by PMR spectroscopy on the basis of chemical shifts and spin-spin coupling constants