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
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
Linear constructs with an N-terminus and a C-terminus which bind to a natriuretic peptide receptor and include a plurality of amino acid residues and at least one amino acid surrogate of formula I:
where R, R′, Q, Y, W, Z, J, x and n are as defined in the specification, and optionally at least one prosthetic group covalently bound to a reactive group of at least one of the amino acid residues or surrogates, pharmaceutical compositions including such linear constructs, and methods of treating congestive heart failure or other conditions, syndromes or diseases for which induction of anti-hypertensive, cardiovascular, renal or endocrine effects are desired.
Catalytic asymmetric direct aldol reaction of α-alkyl azlactones and aliphatic aldehydes
作者:Yang Zheng、Li Deng
DOI:10.1039/c5sc02116b
日期:——
An unprecedented highly diastereoselective and enantioselective aldol reaction of [small alpha]-alkyl azlactones and aliphaticaldehydes was achieved with cinchona alkaloid catalysts. To our knowledge, this reaction provides the first useful catalytic...
Catalytic Asymmetric Inverse‐Electron‐Demand 1,3‐Dipolar Cycloaddition of C,N‐Cyclic Azomethine Imines with Azlactones: Access to Chiral Tricyclic Tetrahydroisoquinolines
作者:Xihong Liu、Yijie Wang、Dongxu Yang、Jinlong Zhang、Dongsheng Liu、Wu Su
DOI:10.1002/anie.201602880
日期:2016.7.4
Reported herein is a bifunctional‐organocatalyst‐mediated enantioselective inverse‐electron‐demand 1,3‐dipolarcycloaddition of C,N‐cyclic azomethine imines with azlactones. The strategy provides concise access to enantioenriched C1‐substituted tetrahydroisoquinolines featuring a pyrazolidinone scaffold. Moreover, the scalability and practical utility of this protocol was well demonstrated by employing