Asymmetric Henry Reaction Catalyzed By Novel Bimetallic Complexes

Optically β-nitro alcohols are key intermediates for the synthesis of pharmaceutical agents,such as salmeterol,propranolol,adrenaline and amprenavir.The catalytic asymmetric Henry reaction is a useful reaction that affords chiral β-nitro alcohols.In this disseration,we have developed an enantioselective Henry reaction catalyzed by novel bimetallic complexes.Part I: Asymmetric Henry reaction catalyzed by a chiral dinuclear nickel complexA series of chiral polyfunctional ligand derived from L-amino acids and 2-hydroxy-5-methylisophthalaldehyde were synthes ized and used to complex with different metal salts.The dinuc lear nickel complex derived from L-phenylglyc ine gave the best results(yield up to 72%,ee up to 91%).The proposed catalytic cycle and trans ition states was described according to the ESI-MS analyses of the catalyst and the experiment results.PartⅡ: Asymmetric Henry reaction catalyzed by a chiral Cu/Sm heterobimetallic complexThe chiral polyfunctional ligand was synthesized from(1R,2R)-1,2-diphenyl ethylene diamine and 2-hydroxy-5-methylisophthalaldehyde and used to complex with different metal salts.The Cu/Sm complex gave the best results for aromatic aldehydes containing electron-withdrawing substituent which could not gave satisfactory results by the dinuc lear nickel complex in part I(yield up to 94%,ee up to 82%).A preliminary analys is on the structure of the heterobimetallic complex was studied by the linear relationship with the ee values between the ligand and the product.