A catalytic enantioselective synthesis of chiral monosubstituted oxiranes
摘要:
A new catalytic enantioselective synthesis of monosubstituted oxiranes has been developed from achiral trichloromethyl ketones by (a) enantioselective carbonyl reduction, (b) selective bis-dechlorination and (c) base-induced ring closure of the resulting chlorohydrins.
A practical method for the asymmetric transferhydrogenation of α‐substituted ketones was developed utilizing oxo‐tethered N‐sulfonyldiamine‐ruthenium complexes. Reduction by HCO2H and HCO2K in a mixed solvent of EtOAc/H2O allowed for the selective synthesis of halohydrins from 2‐bromoacetophenone (98%) and 2‐chloroacetophenone (>99%), leading to suppressed undesired side reactions stemming from formylation
Iridium‐catalyzedasymmetrichydrogenation of prochiral halogenated ketones was successfully developed to prepare various chiral halohydrins with high reactivities and excellent enantioselectivities under basic reaction condition (up to >99% conversion, 99% yield, >99% ee). Moreover, gram‐scale experiment was performed well in the presence of just 0.005 mol% (S/C=20 000) Ir/f‐amphox catalyst with 99%
N-((3-BENZYL)-2,2-(BIS-PHENYL)-PROPAN-1-AMINE DERIVATIVES AS CETP INHIBITORS FOR THE TREATMENT OF ATHEROSCLEROSIS AND CARDIOVASCULAR DISEASES
申请人:Salvati Mark E.
公开号:US20100041717A1
公开(公告)日:2010-02-18
Compounds of formula (Ia) and (Ib), wherein A, B, C, R
1
and R
14
are described herein.
式(Ia)和(Ib)的化合物,其中A、B、C、R1和R14如本文所述。
A facile enzyme assisted route to (R) - and (S)-t-butyloxirane and related β-amino alcohols - catalysts for the enantioselective addition of dialkylzinc reagents to aldehydes
作者:A. Chadha、U. Goergens、M.P. Schneider
DOI:10.1016/s0957-4166(00)80338-9
日期:1993.7
(R) and (S)-t-butyloxirane [(R)- and (S)-3] have been prepared in high enantiomeric purity from racemic t-butyloxirane (±)-3 by an enzymatic route. (S)-3 has been used for the preparation of the chiral β-amino alcohols (R)- and (S)-1,2, which are catalysts for the enantioselectiveaddition of dialkylzinc reagents to aldehydes.
The Ir-Catalyzed Asymmetric Hydrogenation of α-Halogenated Ketones Utilizing Cinchona-Alkaloid-Derived NNP Ligand to Produce (<i>R</i>)- and (<i>S</i>)-Halohydrins
作者:Qian Chen、Hao Sun、Linlin Li、Jie Tian、Qian Xu、Nana Ma、Li Li、Lin Zhang、Chun Li
DOI:10.1021/acs.joc.2c02109
日期:2022.12.2
hydrogenation of α-halogenated ketones with iridium catalyst was developed, utilizing easily accessed cinchona-alkaloid-based NNP ligands. Various α-chloroacetophenones, heterocyclic thienyl and furanyl substrates, and even bromoketones were completely converted to the desired chiral halohydrins by this protocol. Both (R)- and (S)-chiral halohydrins can be prepared by changing the configurations of the chiral
利用易于获取的基于金鸡纳生物碱的 NNP 配体,开发了铱催化剂对 α-卤化酮的不对称氢化。通过该协议,各种 α-氯苯乙酮、杂环噻吩基和呋喃基底物,甚至溴酮完全转化为所需的手性卤代醇。( R )- 和 ( S )- 手性卤代醇都可以通过改变手性配体 NNP 的构型来制备,分别具有高达 99.6% ee(对映体过量)和 98.8% ee。此外,有效地进行了克级实验。