Nitroalkenes prochiral

Michael addition of 1,3-dicarbonyl compounds to conjugated prochiral nitroalkenes catalysed by (acac)2Ni and (acac)2Co has been reported to give up to 30% ee when carried out in the presence of cinchonidine.100... 

A reaction forming enamine adducts between nitroalkenes and enamines takes place with excellent diastereoselectivity572,573 and enantioselectivity. Seebach and coworkers574-577 have proposed a topological rule for the carbon-carbon bond-forming process between prochiral centres in enamines and nitroalkenes. This reaction is very important in the synthesis of enantiomerically pure organic compounds. 

Reactions of nitroalkenes and enamines take place not only in good chemical yields but also in excellent diastereomeric yields (>90%)118. A topological rule has been formulated for carbon-carbon bond-forming processes between prochiral centres in enamines and nitroalkenes as well as other systems119. 

Reactions of nitroalkenes and enamines take place not only in good chemical yields but also in excellent diastereomeric yields (>W%) . A topological rule has been formulated for carbon-carbon bond-forming processes between prochiral centres in enamines and nitroalkenes as well as other systems The reaction of enamines and imines with acrylamide results in aza-annulation ° . Other electrophilic alkenes which have been us to alkylate enamines and the products used in hetero- or carbocyclic synthesis include ethyl /5-nitroacrylate, where reaction occurs beta to the nitro not the ester group, 2- phenylseleno)prop-2-enenitrile [CH2 = C(SePh)CN] , phenyl a-phenylselenovinyl sulphone [CH2 = C(SePh)-S02Ph] and phenyl a-bromovinyl sulphone. An electrophilic allene, phenylsulpho-nylpropadiene, has also been used to alkylate enamines (Scheme 44). 

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