共查询到20条相似文献,搜索用时 56 毫秒
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由天然樟脑合成了两个新的手性氨基醇,并对其在二乙基锌对芳香醛的对映选择性加成中的催化性能进行了研究,其中一个化合物4b催化苯甲醛和二乙基锌的加成反应获得了85%化学产率和73%e.e.。 相似文献
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综述了近年来关于催化不对称硅氢化反应的研究进展,介绍了一些新型的手性催化剂配体的研究情况。并对不对称硅氢化反应未来的研究动向进行了预测。 相似文献
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手性1, 2-氨基醇作为合成砌块常被作为起始原料用于生物活性化合物或手性配体的制备,也可以作为手性辅基被直接用于不对称合成。本文简述了手性氨基醇的主要合成方法,并对近些年合成方法的进展予以整理报道。 相似文献
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促进活性细胞催化前手性羰基不对称还原研究进展 总被引:2,自引:0,他引:2
利用活性微生物细胞催化羰基不对称还原成为手性醇合成的重要方法。虽然当前已经筛选出许多立体选择性很高的微生物和反应过程,但这类反应能实际应用的还很少,主要是因为产业化方面的研究不够。本文从此出发,结合作者近几年的研究工作对当前活性微生物细胞催化羰基不对称还原相关工程方面的研究进行了详细的介绍和论述。分析了利用活性细胞催化时空产率低的原因,对国内外研究者针对这些原因为提高时空产率所进行的各种研究和提出的方法分别进行了归纳和分析。 相似文献
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Chiral aromatic alcohols are the key chiral building block for many important enantiopure pharmaceu-ticals. In this work,we studied asymmetric reduction of prochiral aromatic ketone to produce the corresponding chiral alcohol using vegetables as the biocatalyst. Acetophenone was chosen as the model substrate. The results in-dicate that acetophenone can be reduced to the corresponding chiral alcohols with high enantioselectivity by the chosen vegetables,i.e. apple(Malus pumila),carrot(Daucus carota),cucumber(Cucumis sativus),onion(Allium cepa),potato(Soanum tuberosum),radish(Raphanus sativus),and sweet potato(Ipomoea batatas) . In the reaction,R-1-phenylethanol is produced with apple,sweet potato and potato as the catalyst,while S-1-phenylethanol is the product with the other vegetables as the catalyst. In term of the enantioselectivity and reaction yield,carrot(D. ca-rota) is the best catalyst for this reaction. Furthermore,the reaction characteristics were studied in detail using car-rot(D. carota) as the biocatalyst. The effects of various factors on the reaction were investigated and the optimal reaction conditions were determined. Under the optimal reaction conditions(reaction time 50 h,substrate concen-tration 20 mmol·L-1,reaction temperature 35 °C and pH 7),95% of e.e.(to S-1-phenylethanol) and 85% chemical yield can be obtained. This work extends the biocatalyst for the asymmetric reduction reaction of prochiral aromatic ketones,and provides a novel potential route to produce enantiopure aromatic alcohols. 相似文献
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介绍了一种新颖的具有C2对称性的手性双磷杂环戊烷配体DuPHOS,此配体在烯酰胺类、2-烷基琥珀酸类、α-羟基醌类、开链烯醇酯类、酮类等众多类型底物的不对称催化氢化反应中显示出了极高的对映体选择性,本文对此配体的最新研究进展进行了综述。 相似文献
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Denis Sinou Cedric Rabeyrin Christelle Nguefack 《Advanced Synthesis \u0026amp; Catalysis》2003,345(3):357-363
Asymmetric palladium‐catalyzed alkylation of 1,3‐diphenyl‐2‐propenyl acetate with dimethyl malonate occurs in water in the presence of surfactants and a base. The efficiency as well as the enantioselectivity of the coupling reaction depend strongly on the nature and the concentration of the surfactant. The highest yield and enantioselectivity (up to 91%) was obtained using Binap as the ligand in the presence of a cationic surfactant, while neutral or zwitterionic surfactants gave poorer results; anionic surfactants gave no reaction at all. The best results were obtained using Na2CO3, NaHCO3, or K2CO3, among the bases used. The highest enantioselectivities were obtained when the reaction was performed in the presence of chiral atropoisomeric diphosphines such as Binap, Biphemp, or MeOBiphep. A supported cationic surfactant was also used successfully in this reaction, allowing an easier separation of the product. 相似文献
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MiquelA. Perics David Castellnou Israel Rodríguez Antoni Riera Lluís Sol 《Advanced Synthesis \u0026amp; Catalysis》2003,345(12):1305-1313
A functional analogue of (R)‐2‐piperidino‐1,1,2‐triphenylethanol was synthesized and anchored to different polymeric supports by a position remote from the active region. This strategy, leading to what we call a tail‐tied ligand, allows for the achievement of the optimal transition state geometry in the catalytic process. The catalytic activity of the resulting heterogenized ligands was investigated by online FTIR analysis. The optimum polymer was assayed in the addition reaction of diethylzinc to a large family of aldehydes rendering essentially intact high catalytic activity and enantioselectivity compared to its homogeneous counterpart. 相似文献
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Jiwu Ruan Gui Lu Lijing Xu Yue‐Ming Li Albert S.C. Chan 《Advanced Synthesis \u0026amp; Catalysis》2008,350(1):76-84
A novel chiral H8‐1,1′‐binaphthyl‐based amino alcohol ligand (1Ra,2S,3R)‐ 2 has been synthesized and applied in the direct nucleophilic addition of organozincs (alkynylzinc and arylzinc prepared in situ) to aldehydes, yielding the corresponding optically active propargylic alcohols and diarylmethanols in high yields and good to excellent enantioselectivities. For the asymmetric arylation reaction, one catalyst (1Ra,2S,3R)‐ 2 can afford both enantiomers of many pharmaceutically interesting diarylmethanols by a proper combination of various arylzinc reagents and aldehydes. 相似文献