A novel reaction has been discovered with a mechanism similar to the Baylis
-Hillman reaction. Reaction of a vinylic phosphine oxide with (R)-N-lithio-
alpha -methylbenzylbenzylamine 2 in the presence of an aldehyde gave hydrox
yphosphine oxides in good to moderate yields and moderate to poor enantiose
lectivities. The hydroxyphosphine oxides undergo the Horner-Wittig eliminat
ion reaction to produce allenes. Baylis-Hillman reactions of vinylic phosph
ine oxides with tertiary amines were also investigated.