Metal-free regioselective hydrophosphorylation of electron-deficient alkynes catalyzed by oxazaborolidines

Here, we describe a metal-free strategy for the hydrophosphorylation of electron-deficient alkynyl to access various P-containing olefins catalyzed by commercial oxazaborolidines with high regio-selectivity (<i>E</i> : <i>Z</i> up to 99%). Interestingly, the possible mechanism suggests that the catalytic path proceeds through a synergistic addition process which leads to single <i>E</i>-structure products. Moreover, the chiral oxazaborolidine catalyst probably works as a Lewis pair which can accelerate the cleavage of the O-H bond in diarylphosphine oxides and provide appropriate steric hindrance to control the regioselectivity.