A step-economic and one-pot access to chiral C<sup>α</sup>-tetrasubstituted α-amino acid derivatives <i>via</i> a bicyclic imidazole-catalyzed direct enantioselective <i>C</i>-acylation
Cα-Tetrasubstituted α-amino acids are ubiquitous and unique structural units in bioactive natural products and pharmaceutical compounds. The asymmetric synthesis of these molecules has attracted a lot of attention, but a more efficient method is still greatly desired. Here we describe the first sequential four-step acylation reaction for the efficientsynthesis of chiral Cα-tetrasubstituted α-amino acid derivatives
Group-Assisted Purification Chemistry for Asymmetric Mannich-type Reaction of Chiral <i>N</i>-Phosphonyl Imines with Azlactones Leading to Syntheses of α-Quaternary α,β-Diamino Acid Derivatives
作者:Haowei Zhang、Zhen Yang、Brian Nlong Zhao、Guigen Li
DOI:10.1021/acs.joc.7b02556
日期:2018.1.19
An asymmetric Mannich-type reaction between chiral N-phosphonyl imines and azlactones [oxazol-5(4H)-ones] has been established under convenient conditions at room temperature. The reaction was performed without using any bases, additives, or catalysts to achieve up to excellent chemical yields and diastereoselectivity for 32 examples. The α-quaternary syn-α,β-diamino acid products were purified simply
Nickel-Catalyzed Multicomponent Coupling: Synthesis of α-Chiral Ketones by Reductive Hydrocarbonylation of Alkenes
作者:Jian Chen、Shaolin Zhu
DOI:10.1021/jacs.1c07851
日期:2021.9.8
functionalized α-stereocenter, including enantioenriched chiral α-aryl ketones and α-amino ketones. It useschiral bisoxazoline as a ligand, silane as a reductant, chloroformate as a safe CO source, and a racemic secondary benzyl chloride or an N-hydroxyphthalimide (NHP) ester of a protected α-amino acid as the alkylation reagent. The benign nature of this process renders this method suitable for late-stage functionalization
已经开发出一种镍催化、多组分区域选择性和对映选择性偶联,通过顺序加氢甲酰化和羰基化从容易获得的起始材料中进行。这种模块化的多组分加氢官能化策略能够对各种未活化的烯烃进行直接的还原烃基化,以产生各种带有功能化 α-立体中心的不对称二烷基酮,包括对映体富集的手性 α-芳基酮和 α-氨基酮。它使用手性双恶唑啉作为配体,硅烷作为还原剂,氯甲酸酯作为安全的 CO 源,外消旋仲苄基氯或N受保护的 α-氨基酸的 -羟基邻苯二甲酰亚胺 (NHP) 酯作为烷基化试剂。该过程的良性性质使该方法适用于复杂分子的后期功能化。
Synthesis and Cytotoxicity of N-(3,4-Dimethoxyphenyl)Ethylamides of N-Benzoyl-α-Amino Acids
作者:D. B. Tukhtaev、A. Sh. Saidov、M. Alimova、E. O. Terent’eva、Z. S. Khashimova、Sh. S. Azimova、V. I. Vinogradova
DOI:10.1007/s10600-019-02782-9
日期:2019.7
Amides were synthesized from N-benzoyl aliphatic α-amino acids and homoveratrylamine and screened for cytotoxicity.
Asymmetric Aza-Diels–Alder Reactions of in Situ Generated β,β-Disubstituted α,β-Unsaturated N–H Ketimines Catalyzed by Chiral Phosphoric Acids
作者:Shunlong He、Huanchao Gu、Yu-Peng He、Xiaoyu Yang
DOI:10.1021/acs.orglett.0c01994
日期:2020.7.17
A novel asymmetricsynthesis of dihydropyridinones with vicinal quaternary stereocenters has been realized by asymmetric aza-Diels–Alder reactions of 3-amido allylic alcohols with oxazolones enabled by chiral phosphoric acid catalysis. A series of aryl/alkyl- and alkyl/alkyl-disubstituted 3-amido allylic tertiary alcohols and 4-substituted oxazolones could be well tolerated in these reactions, producing