Organophosphorus additive phosphine oxides

A Michael-type addition reaction of phosphine generated from red phosphorus in concentrated aqueous KOH solution has been noted to provide moderate isolable yields of pure organophosphorus products.27 For example, tris-(2-cyanoethyl)phosphine is produced in 45% isolable yield from acrylonitrile, and tris-(2-[y-pyridyl]ethyl) phosphine oxide is isolated in 40% yield from 4-vinylpyridine under these conditions. Excellent yields of the tertiary phosphine oxide, tris-(2-cyanoethyl)phosphine oxide, have been reported using white phosphorus in absolute ethanol with KOH at ice/salt-bath temperatures.28 A variety of solvent systems were examined for this reaction involving a Michael-type addition to acrylonitrile. Similarly, tris-(Z-styryl)phosphine is produced from phenylacetylene under these conditions in 55% isolated yield. It is noteworthy that this last cited reaction involves stereospecific syn- addition of the phosphine to the alkyne. 

A noteworthy synthetic application for the reaction of J with a,g-unsaturated phosphoryl compounds is represented by the addition involving hitherto unknown (-)-(Sp)-methylphenylvinylphosphine oxide J 2. The resulting tertiary phosphine oxides 13 with saturated carbon chains and known stereochemistry at phosphorus constitute attractive starting materials for the preparation of optically pure phosphines. The organophosphorus substrate 12 was obtained by decarbomenthoxylation of the enantiomeric ester... 

---