A new ligand,3,6-bis（9-O-quinidine）pyridazine（（QD）2PYDZ）,was synthesized from quinidine and 3,6-dichloropyridazine under mild condition.It can be purified by recrystallization to give the yield of 73%.The use of...A new ligand,3,6-bis（9-O-quinidine）pyridazine（（QD）2PYDZ）,was synthesized from quinidine and 3,6-dichloropyridazine under mild condition.It can be purified by recrystallization to give the yield of 73%.The use of（QD）2 PYDZ in asymmetric dihydroxylation（AD）of olelfins provided the corresponding chiral vicinal diols with 88～95%chemical yield and the values of enantiomeric excess（ess）are between 75% and 99%.Meanwhile,chiral β-amino alcohols with excellent eantioselectivity and regioselectivity were also achieved when the asymmetric aminohydroxylation（AA）of olefins were catalyzed by the complex（QD）2PYDZ-Os04.Their chemical yields ranged from 52%to 63%.In addition,during the AD reaction of ethyl trans-cinnamate,（QD）2PYDZ can be recovered and reused for five runs without any signilficant loss in its catalytlc efficiency.展开更多
A chiral cinchona alkaloid derivative, which can be recovered and reused in asymmetric dihydroxylation (AD) reaction, was easily prepared from 1,4-dichlorophthalazine by two steps. The total yield is 87.4%. Applicatio...A chiral cinchona alkaloid derivative, which can be recovered and reused in asymmetric dihydroxylation (AD) reaction, was easily prepared from 1,4-dichlorophthalazine by two steps. The total yield is 87.4%. Application of this ligand to the AD reaction of six olefins afforded corresponding chiral diols in 92%～98% and 86%～99% ee. After the catalytic reaction, the ligand can be got by filtration from diethyl ether and reused for five runs with good yields and excellent enantioseletivity unchanged.展开更多
文摘A new ligand,3,6-bis（9-O-quinidine）pyridazine（（QD）2PYDZ）,was synthesized from quinidine and 3,6-dichloropyridazine under mild condition.It can be purified by recrystallization to give the yield of 73%.The use of（QD）2 PYDZ in asymmetric dihydroxylation（AD）of olelfins provided the corresponding chiral vicinal diols with 88～95%chemical yield and the values of enantiomeric excess（ess）are between 75% and 99%.Meanwhile,chiral β-amino alcohols with excellent eantioselectivity and regioselectivity were also achieved when the asymmetric aminohydroxylation（AA）of olefins were catalyzed by the complex（QD）2PYDZ-Os04.Their chemical yields ranged from 52%to 63%.In addition,during the AD reaction of ethyl trans-cinnamate,（QD）2PYDZ can be recovered and reused for five runs without any signilficant loss in its catalytlc efficiency.
文摘A chiral cinchona alkaloid derivative, which can be recovered and reused in asymmetric dihydroxylation (AD) reaction, was easily prepared from 1,4-dichlorophthalazine by two steps. The total yield is 87.4%. Application of this ligand to the AD reaction of six olefins afforded corresponding chiral diols in 92%～98% and 86%～99% ee. After the catalytic reaction, the ligand can be got by filtration from diethyl ether and reused for five runs with good yields and excellent enantioseletivity unchanged.
