共查询到18条相似文献,搜索用时 78 毫秒
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用分级结晶或柱层析方法对2-(2-吡啶基)-4-羧甲基-1,3-噻唑烷及2-甲基-2(2-吡啶基)-4-羧甲基-1,3-噻唑烷两种手性配体进行提纯,分别考察了其与」Rh(COD)Cl「2制备的在位催化剂催化苯乙酮的不对称硅氢化反应,发现只有噻唑烷环上的C4位手性中心对催化反应结果有影响,其C2位手性中心在Rh(I)催化下发生了快速差向异构化反应。 相似文献
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手性茂金属催化剂在不对称硅氢化反应中的应用 总被引:2,自引:0,他引:2
手性茂金属催化剂在不对称硅氢化反应中的应用研究近扯为取得了很大进展。对90年代以来具有高手性诱导效应的手性二茂铁络合催化剂及手性二茂钛系催化剂进行了重点评述,并展望了其应用研究前景。 相似文献
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将BoPhoz类膦-氨基膦配体应用在Rh-催化β-脱氢氨基酸酯的不对称氢化反应中,考察了配体结构及反应条件对反应结果的影响,并在优化的条件下研究了各种底物的适用范围,产物的对映选择性达81%ee. 相似文献
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噻唑烷类配体的手性结构及其在催化苯乙酮不对称硅氢化反应中的应用研究 总被引:1,自引:0,他引:1
用分级结晶或柱层析方法对2-(2-吡啶基)-4-羧甲基-1,3-噻唑烷(A)及2-甲基-2-(2-吡啶基)-4-羧甲基-1,3-噻唑烷(B)两种手性配体进行提纯,分别考察了其与[Rh(COD)Cl]2制备的在位催化剂催化苯乙酮的不对称硅氢化反应,发现只有噻唑烷环上的C4位手性中心对催化反应结果有影响,其C2位手性中心在Rh(1)催化下发生了快速差向异构化反应. 相似文献
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本文以类球红杆菌(Rhodobacter sphaeroides)为生物催化剂, 将苯乙酮催化还原成具有光学活性的手性醇. 研究了反应条件对该反应的影响. 相似文献
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C. González J. I. Gutiérrez J. R. González-Velasco A. Cid A. Arranz J. F. Arranz 《Journal of Thermal Analysis and Calorimetry》1998,52(3):985-989
The aim of this work was to study the thermal transitions of several manganese oxides (MnO, MnOOH, Mn2O3, Mn3O4 and MnO2) under reducing conditions. Differential scanning calorimetry (DSC) was used to analyse the transitions of some oxides into
others. A comparison of the behavior of the synthetic samples with that of a natural manganese dioxide demonstrated that DSC
is a quick tool for the distinction of natural manganese dioxide from synthetic γ-MnO2 from other manganese oxides.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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在硅烷化硅胶上涂敷手性高分子配位体三苯基氨基甲酸纤维素酯和三(3,5-二甲基苯基氨基甲酸)纤维素酯,然后与PdCl3配位,制备一种新型的负载型不对称加氢催化剂,该催化剂用于苯乙酮的加氢反应,醇收率最高达100%,但产物的对遇选择性较低的原因。 相似文献
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采用苯乙酮为模式底物,选用了3种典型的离子液体作为反应介质系统研究了离子液体与缓冲液构成的均相及两相体系中固定化光合细菌催化不对称还原反应的特性.通过对构建的离子液体反应体系进行条件优化,发现与水相及有机相相比,离子液体作为生物催化反应介质更有利于还原反应的进行,并且离子液体及固定化细胞易回收重复利用.研究结果表明,在... 相似文献
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Dr. Sukalyan Bhadra Prof. Dr. Hisashi Yamamoto 《Angewandte Chemie (International ed. in English)》2016,55(42):13043-13046
Direct asymmetric synthesis of N‐chiral amine oxides was accomplished (up to 91:9 e.r.) by means of a bimetallic titanium catalyst. A hydroxy group situated at the γ‐position of the N stereocenter enables the desired N‐oxidation through dynamic kinetic resolution of the trivalent amine substrates. The method was further extended to the kinetic resolution of racemic γ‐amino alcohols with a preexisting stereocenter, giving an important class of enantioenriched (up to 99.9:0.1 e.r.) building blocks that are otherwise difficult to synthesize. 相似文献
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Asymmetric Hydrogenation of Ketones and Enones with Chiral Lewis Base Derived Frustrated Lewis Pairs
Bochao Gao Xiangqing Feng Wei Meng Haifeng Du 《Angewandte Chemie (International ed. in English)》2020,59(11):4498-4504
The concept of frustrated Lewis pairs (FLPs) has been widely applied in various research areas, and metal‐free hydrogenation undoubtedly belongs to the most significant and successful ones. In the past decade, great efforts have been devoted to the synthesis of chiral boron Lewis acids. In a sharp contrast, chiral Lewis base derived FLPs have rarely been disclosed for the asymmetric hydrogenation. In this work, a novel type of chiral FLP was developed by simple combination of chiral oxazoline Lewis bases with achiral boron Lewis acids, thus providing a promising new direction for the development of chiral FLPs in the future. These chiral FLPs proved to be highly effective for the asymmetric hydrogenation of ketones, enones, and chromones, giving the corresponding products in high yields with up to 95 % ee. Mechanistic studies suggest that the hydrogen transfer to simple ketones likely proceeds in a concerted manner. 相似文献