Iridium and Rhodium Complexes Containing Enantiopure Primary Amine-Tethered <i>N</i>-Heterocyclic Carbenes: Synthesis, Characterization, Reactivity, and Catalytic Asymmetric Hydrogenation of Ketones
作者:Kai Y. Wan、Florian Roelfes、Alan J. Lough、F. Ekkehardt Hahn、Robert H. Morris
DOI:10.1021/acs.organomet.7b00915
日期:2018.2.12
a bimetallic iridium compound with (S,S)-11 as the bridging ligand. This compound contains interesting NH···Cl and NH···Ir noncovalent intramolecular interactions. Salt (S,S)-12·HPF6 reacts with silver oxide to yield [Ag2((S,S)-12)2](PF6)2 (20). Reagent 20 serves as an efficient transmetalation reagent to deliver to each rhodium in [RhCl(cod)]2 1 equiv of (S,S)-12 as a bidentate ligand to give [Rh(cod)((S
Chiral C2-symmetric η6-p-cymene-Ru(II)-phosphinite complexes: Synthesis and catalytic activity in asymmetric reduction of aromatic, methyl alkyl and alkyl/aryl ketones
Abstract Chiral C2-symmetric bis(phosphinite) ligands and their binuclearruthenium(II) complexes have been synthesized and used as catalysts in the ruthenium-catalyzed asymmetrictransferhydrogenation of aromatic, methyl alkyl and alkyl/aryl ketones using 2-propanol as both the hydrogen source and solvent in the presence of KOH. Under optimized conditions, all complexes showed high catalytic activity
Production of enantiomerically enriched chiral carbinols using whole-cell biocatalyst
作者:Yasemin Baydaş、Erbay Kalay、Engin Şahin
DOI:10.1080/10242422.2020.1837782
日期:2022.1.2
(R)-4-Phenyl-2-butanol 2a, which is used as a precursor to antihypertensive agents and spasmolytics (anti-epileptic agents), was obtained using L kefiri P2 in 99% conversion and 91% enantiomeric excess (ee). Moreover, bioreduction of 2-methyl-1-phenylpropan-1-one substrate 8, containing a branched alkyl chain and difficult to asymmetric reduction with chemical catalysts as an enantioselective, to (R)-2-methyl-1-phenylpropan-1-ol
摘要 酮的生物催化不对称还原是生产手性甲醇的有效方法。该研究表明,不同酮类 ( 1-8 ) 以低至高选择性 (0->99%)选择性生物还原为它们各自的 ( R )-醇 ( 1a-8a ),产率良好 (11-96%)。在这项工作中,研究了开菲尔乳杆菌P2的全细胞催化的各种前手性酮的对映选择性还原。( R )-4-Phenyl-2-butanol 2a,用作抗高血压药和解痉药(抗癫痫药)的前体,使用L kefiri获得P2 转化率为 99%,对映体过量 (ee) 为 91%。此外,2-methyl-1-phenylpropan-1-one 底物8(含有支链烷基链且难以用化学催化剂作为对映选择性的不对称还原)生物还原为 ( R )-2-methyl-1-phenylpropan-1-对映体纯形式的ol (8a)以优异的产率(96%)进行。进行克级生产,以96%的收率获得9.70g对映体纯形式的(
Enantioselective reduction of prochiral ketones using spiroborate esters as catalysts
作者:Viatcheslav Stepanenko、Melvin De Jesús、Wildeliz Correa、Irisbel Guzmán、Cindybeth Vázquez、Wilanet de la Cruz、Margarita Ortiz-Marciales、Charles L. Barnes
DOI:10.1016/j.tetlet.2007.06.086
日期:2007.8
spiroborate esters derived nonracemic 1,2-aminoalcohols and ethylene glycol are reported as highly effective catalysts for the asymmetric borane reduction of a variety of prochiral ketones with borane-dimethylsulfidecomplex at room temperature. Optically active alcohols were obtained in excellent chemical yields using 0.1 to 10 mol % of catalysts with up to 99% ee.
据报道,衍生自非外消旋 1,2-氨基醇和乙二醇的新型螺硼酸酯是室温下各种前手性酮与硼烷-二甲硫醚络合物的不对称硼烷还原反应的高效催化剂。使用 0.1 至 10 mol% 的催化剂和高达 99% ee 以优异的化学产率获得光学活性醇。
Highly enantioselective carbonyl reduction with borane catalyzed by chiral spiroborate esters derived from chiral beta-aminoalcohols
申请人:Ortiz-Marciales Margarita
公开号:US20080200672A1
公开(公告)日:2008-08-21
Novel spiroborate esters derived from non-recemic 1,2-amino alcohols were examined as chiral catalyst in the borane reduction of acetophenone and other aromatic ketones at room temperature. The optically active alcohols were obtained in excellent chemical yields and up to 99% ee with less than 10% catalyst.