Intermolecular Hydrophosphination of Alkynes and Related Carbon−Carbon Multiple Bonds Catalyzed by Organoytterbiums

Abstract
Intermolecular hydrophosphination of alkynes with diphenylphosphine is catalyzed by a Yb−imine complex, [Yb(η2-Ph2CNPh)(hmpa)3], to give alkenylphosphines and phosphine oxides after oxidative workup in good yields under mild conditions. This reaction is also applicable to various carbon−carbon multiple bonds such as conjugated diynes and dienes, allenes, and styrene derivatives. Regio- and stereoselectivity and the scope and limitation of the present reaction clearly differ from those of the corresponding radical reaction. Instead, the reaction takes place through insertion of alkynes to a Yb−PPh2 species, followed by protonation. In fact, the Yb−phosphido complex, [Yb(PPh2)2(hmpa)3], is obtained from the imine complex and phosphine, which exhibits similar catalyst activity for the hydrophosphination. The empirical rate law is ν = k[catalyst]2 [alkyne]1[phosphine]0 at least under the standard conditions.

This publication has 17 references indexed in Scilit: