Heterogeneous Synergistic Catalysis for Promoting Aza-Michael–Henry Tandem Reaction for the Synthesis of Chiral 3-Nitro-1,2-Dihydroquinoline

Heterogeneous synergistic catalysis by SBA-15 immobilized chiral amines catalysts has promoted efficient aza-Michael–Henry tandem reaction for the synthesis of chiral 3-Nitro-1,2-Dihydroquinoline. Final products in the asymmetric aza-Michael–Henry cascade reactions between 2-aminobenzaldehyde and β-nitrostyrolene were afforded in a yield of 85% and an enantiomeric excess (ee) value of 98% on (S)-(–)-2-aminomethyl-1-ethylpyrrolidine immobilized SBA-15. SBA-15-AEP catalyst has been also extended to the asymmetric aza-Michael–Henry cascade reaction of substituted R1-2-aminobenzaldehyde and R2-substituted nitroolefin. The heterogeneous synergistic mechanism for both tertiary amine and secondary amine immobilized mesoporous has been proposed in detail including the geometrical constraints in the ee promotion.