Organocatalytic highly enantioselective nitroaldol reaction of alpha-ketophosphonates and nitromethane

The first organocatalytic highly enantioselective nitroaldol reaction of alpha-ketophosphonates and nitromethane has been realized by using cupreine (2) or 9-O-benzylcupreine (3) as the catalyst. Both catalysts are highly reactive and highly enantioselective. alpha-Hydroxy-beta-nitrophosphonates have been synthesized in good yields and excellent enantioselectivities (>= 90% ee) at a low catalyst loading (5 mol %). These nitroaldol products may be reduced to the biologically significant beta-amino-alpha-hydroxyphosphonates with complete retention of the stereochemistry.