Stereoselective Addition of Nitromethane

Nitromethane easily adds to carbonyl derivatives in a process also known as the nitroaldol or Henry reactions. The enantioselective addition on prochiral carbonyls can be carried out under asymmetric catalysis mainly using copper and zinc organometallic complexes . Organocatalytic methods find only limited applications in nitroaldol reactions being especially applied in diastereoselective processes and in the addition of nitromethane to activated ketone derivatives. The asymmetric aza version of the nitroaldol reaction (the aza-Henry reaction) with nitromethane is also possible using highly reactive N-acylaldimino derivatives. The latter electrophilic species can be freshly prepared before their utilization or generated in situ from suitable precursors. Finally, addition of nitromethane to N-sulfonylketimines and optically active N-sulfinylketimines readily provides an efficient entry to enantioenriched nitramino derivatives bearing a quaternary stereocenter.