Diastereo- and enantioselective nitro-Mannich reaction of α-substituted nitroacetates to N-phosphoryl imines catalyzed by cinchona alkaloid thiourea organocatalysts

Abstract

The asymmetric nitro-Mannich reaction of N-phosphoryl imines with α-substituted nitroacetates was performed by using cinchona alkaloid thioureas as organocatalysts in toluene at -20 °C. The present method was highly tolerable to functionalized N-phosphoryl imines and provided a reliable synthetic route to obtain the corresponding β-nitro ethylphosphoramidates with adjacent quaternary and tertiary chiral centers in high yield (up to 86%) and high enantiostereoselectivity (up to 99% ee) and diastereoselectivity (up to 99 : 1, anti-selectivity).