Rhodium-catalyzed asymmetric hydrogenation of unprotected β-enamine phosphonates

We have successfully developed a strategy for the first time for the enantioselective Rh-TaniaPhos catalyzed asymmetric hydrogenation of unprotected beta-enamine phosphonates to free beta-amino phosphonates directly with good enantioselectivities (80%-86% ee) and high conversions (>99% conversion). The resulting chiral free beta-amino phosphonates and their derivatives are important intermediates in biochemistry and pharmaceuticals.