| Abstract
| - Intermolecular hydrophosphination of alkynes with diphenylphosphine is catalyzed by a Yb−iminecomplex, [Yb(η2-Ph2CNPh)(hmpa)3], to give alkenylphosphines and phosphine oxides after oxidativeworkup 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 thoseof the corresponding radical reaction. Instead, the reaction takes place through insertion of alkynesto 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 activityfor the hydrophosphination. The empirical rate law is ν = k[catalyst]2 [alkyne]1[phosphine]0 at leastunder the standard conditions.
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