Twelve chiral copper(Ⅱ) Schiff base complexes, derived from (R) (+) 2 amino 1,1 diaryl 1 propanol with substituted salicylaldehydes, were examined as a catalyst for asymmetric cyclopropanation of styrene with ethyl d...Twelve chiral copper(Ⅱ) Schiff base complexes, derived from (R) (+) 2 amino 1,1 diaryl 1 propanol with substituted salicylaldehydes, were examined as a catalyst for asymmetric cyclopropanation of styrene with ethyl diazoacetate. It was found that the substituents at 3 and 5 positions of salicylaldehyde in the ligands had great effects on catalytic activity and enantioselectivity of the catalyst. The complex with strong electron withdrawing group (NO 2) at 5 position and the smallest stereo hinder (H) at 3 position of salicylaldehyde showed highly catalytic activity and enantioselectivity, up to ee =87 4% for trans and ee =82 8% for cis isomers respectively, and the ratio 39/61 of cis to trans isomers was obtained at 40 ℃ with 1,2 dichloroethane as solvent.展开更多
An amphipathic Schiff base complex with Cu(Ⅱ) was synthesized from p-cresol a nd dodecanoyl chloride with total yield of 36 8%. The structure and amphipathic property of the ligand and Cu complex have been invest iga...An amphipathic Schiff base complex with Cu(Ⅱ) was synthesized from p-cresol a nd dodecanoyl chloride with total yield of 36 8%. The structure and amphipathic property of the ligand and Cu complex have been invest igated. The oxidation of benzyl alcohol catalyzed by the complex in alkali solution gave benzaldehyde in yield of 57 8%.展开更多
文摘Twelve chiral copper(Ⅱ) Schiff base complexes, derived from (R) (+) 2 amino 1,1 diaryl 1 propanol with substituted salicylaldehydes, were examined as a catalyst for asymmetric cyclopropanation of styrene with ethyl diazoacetate. It was found that the substituents at 3 and 5 positions of salicylaldehyde in the ligands had great effects on catalytic activity and enantioselectivity of the catalyst. The complex with strong electron withdrawing group (NO 2) at 5 position and the smallest stereo hinder (H) at 3 position of salicylaldehyde showed highly catalytic activity and enantioselectivity, up to ee =87 4% for trans and ee =82 8% for cis isomers respectively, and the ratio 39/61 of cis to trans isomers was obtained at 40 ℃ with 1,2 dichloroethane as solvent.
文摘An amphipathic Schiff base complex with Cu(Ⅱ) was synthesized from p-cresol a nd dodecanoyl chloride with total yield of 36 8%. The structure and amphipathic property of the ligand and Cu complex have been invest igated. The oxidation of benzyl alcohol catalyzed by the complex in alkali solution gave benzaldehyde in yield of 57 8%.
