Reactions of red phosphorus and phosphine with electrophilies in superbasic systems: X. Phosphorylation of 2-vinylpyridine with elemental phosphorus and phosphine in the system KOH-DMSO

Red phosphorus reacts with 2-vinylpyridine in the superbasic suspension KOH -dimethyl sulfoxide (DMSO) to give tris[2-(2-pyridyl)ethyl]phosphine oxide in an yield of 52%. Under similar conditions, the triad white phosphorus-KO H-DMSO phosphorylates 2-vinylpyridine more efficiently: The yield of tris[2 -(2-pyridyl)ethyl]phosphine oxide is as high as 72%. The nucleophipic addit ion of phosphine generated from red phosphorus and potassium hydroxide at t he double bond of 2-vinylpyridine in the system KOH-DMSO yields 2-(2-pyridy l)ethyl-, bis[2-(2-pyridyl)ethyl]-, and tris[2-(2-pyridyl)ethyl]phosphines. Conditions for selective formation of the secondary and tertiary phosphine s in high yields were found.