The Application Of Chiral Aza Four-membered Ring Amide In Small Molecules Organic Catalysis

Small-molecule nitrogen-containing organocatalysts are developed rapidly, because of their facile raw material, easy synthetic methods and environment-friend. This paper designed and synthesized several chiral nitrogen-containing heterocyclic four-membered ring amide of chiral catalysts, studies its application in catalytic asymmetric Aldol reaction, and acquired better catalytic effect.1. Synthesis of Aza four-membered ring Amide chiral catalystStarting from available (S)-methyl azetidine-2-carboxylate or (existing laborato ry), after three-steps reactions, we obtain optically pure several new chiral N-heterocyclic four-membered ring amide catalysts, and we also explored the synthesis conditions and studdied the methods. The structures of related products were characterized by NMR et al.2. Application in direct asymmetric Aldol reactionAldol reaction is one of the important reactions of C-C bond,and has a wide range of applications in total synthesis. This paper will tell of the synthesis of several N-heterocyclic four-membered ring amide of chiral catalysts and the studies of their application in acetone and benzaldehyde of hydroxyl aldehyde condensation reaction. we screen out the best catalyst, optimized conditions, expand even different substituents aldehydes and ketones contain acetone and ring kotone in this reaction, and has obtained the good corresponding selectivity.The optimal conditions of the reaction system in acetone with aldehydes is tested, for 0℃, brine as solvent, catalyst for 5 mol %, reaction time 2-3 d, achieves the best catalytic effect, when substituents for 2 -nitro, e.e. value up to 96%.The reaction system of in cyclohexanone with aldehydes in the optimal conditions, tested for - 20℃, chloroform as solvent, ligand dosage for 5 mol %, reaction time 2-3 d, achieved the best catalytic effect, when substituents is contrapuntal methyl reached 99.9% e.e. value and 84/14 of dr values.This paper also examines the cyclopentanone with aldehydes reaction and the reaction conditions is same to cyclohexanone, obtained the corresponding well selective of 98.7% e.e., but not only for corresponding diastereoselective poorer to34/66, and so did the cis-regulatory product more.