Asymmetric Hydrogenation of Ketones and Enones with Chiral Lewis Base Derived Frustrated Lewis Pairs
作者:Bochao Gao、Xiangqing Feng、Wei Meng、Haifeng Du
DOI:10.1002/anie.201914568
日期:2020.3.9
The concept of frustratedLewispairs (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 Lewisbase derived FLPs have rarely been disclosed for the asymmetric hydrogenation.
ASYMMETRIC HYDROGENATION METHOD FOR KETONE COMPOUND
申请人:Zhang Wanbin
公开号:US20130053574A1
公开(公告)日:2013-02-28
The invention relates to an asymmetric hydrogenation method for ketone compounds, comprising the step of: under hydrogen atmosphere, in the presence of an in situ catalyst derived from a chiral ligand and a ruthenium salt, adding a ketone compound and a base into a second solvent to carry out an asymmetric hydrogenation for the ketone compound. The invention can obtain a conversion of 100% and a highest asymmetric inducement effect of 99.7% for the ketone compound. The invention has the advantages including simple procedure, high conversion and selectivity, good atom economy and good prospect of industrial application.
Preparative asymmetric reduction of ketones in a biphasic medium with an (S)-alcohol dehydrogenase under in situ-cofactor-recycling with a formate dehydrogenase
The substrate range of a novel recombinant (S)-alcohol dehydrogenase from Rhodococcus erythropolis is described. In addition, an enzyme-compatible biphasic reaction medium for the asymmetric biocatalytic reduction of ketones with in situ-cofactor regeneration has been developed. Thus, reductions of poorly water soluble ketones in the presence of the alcohol dehydrogenase from R. erythropolis and a
Enzyme stereoselectivitycontrol is still a major challenge. To gain insight into the molecular basis of enzyme stereo‐recognition and expand the source of antiPrelog carbonyl reductase toward β‐ketoesters, rational enzyme design aiming at stereoselectivity inversion was performed. The designed variant Q139G switched the enzyme stereoselectivity toward β‐ketoesters from Prelog to antiPrelog, providing
酶的立体选择性控制仍然是主要挑战。为了深入了解酶立体识别的分子基础,并将antiPrelog羰基还原酶的来源扩展至β-酮酸酯,进行了针对立体选择性反转的合理酶设计。设计的Q139G变体将酶对β-酮酸酯的立体选择性从Prelog切换为antiPrelog,从而提供了相应的具有高对映体纯度(89.1–99.1%ee)的醇。更重要的是,在立体选择性和活性之间未找到众所周知的折衷方案。Q139G表现出比野生型酶更高的催化活性,提高了催化效率(k cat / K m)从1.1到27.1倍不等。有趣的是,突变体Q139G并未导致对芳族酮的立体选择性反转。酶-底物复合物的分析表明,β-酮酸酯的结构柔韧性和新形成的空穴共同促进了抗Prelog-首选构象的形成。相比之下,芳族酮的相对较大和刚性的结构阻止了它们形成抗Prelog优先的构象。
Fine-tuning of the substrate binding mode to enhance the catalytic efficiency of an <i>ortho</i>-haloacetophenone-specific carbonyl reductase
Carbonyl reductase BaSDR1 has been identified as a potential ortho-haloacetophenone-specific biocatalyst for the synthesis of chiral 1-(2-halophenyl)ethanols due to its excellent stereoselectivity. However, the catalytic efficiency of BaSDR1 is far below the required level for practical applications. Thus, fine-tuning of the substrate binding mode, which aimed at maximum preservation of the positive