Catalytic compositions and methods for asymmetric aldol reactions

A method of conducting an enantioselective aldol reaction between an aldehyde and a donor molecule selected from a ketone bearing an α-hydrogen and a nitroalkyl compound, the method comprising

• contacting said aldehyde and said donor molecule in the presence of a catalytic amount of an asymmetric catalyst, wherein said catalyst is a complex of a Group 2A or Group 2B metal with a chiral ligand of formula I:
• where
• R1-R4 are aryl groups, which may be the same or different, each of which is unsubstituted or substituted with one or more substituents X, where each X is independently selected from alkyl, alkenyl, alkynyl, aryl, aralkyl, aralkenyl, aralkynyl, alkoxy, aryloxy, amide, alkyl- or aryl sulfonyl, sulfonamide, hydroxy, cyano, nitro, and halogen,
• wherein R1 and R2, or R3 and R4, or both of these combinations, may be linked at an α-carbon of each said group to form a tricyclic or larger ring system;
• m is an integer from 0 to 3;
• each of R5 and R6 represents one or more substituents independently selected from the group consisting of hydrogen and X as defined above;
• and
• R7 represents one or more substituents on the phenol ring independently selected from the group consisting of hydrogen, X as defined above, and a further fused ring;
• under conditions effective to produce an aldol reaction product which is enriched in one of the possible stereoisomeric products of such reaction.