scholarly journals Enamine Catalysis in Flow with an Immobilized Peptidic Catalyst

ChemSusChem ◽  
2013 ◽  
Vol 6 (2) ◽  
pp. 212-212 ◽  
Author(s):  
Yukihiro Arakawa ◽  
Helma Wennemers
Keyword(s):  
Enamine Catalysis

scholarly journals A hidden catalysis: metal-, and organocatalyst-free one-pot assembly of chiral aza-tricyclic molecules containing six contiguous stereocenters

2020 ◽  
Author(s):  
Dung Do
Keyword(s):  
Chemical Space ◽  
Structural Diversity ◽  
Therapeutic Agents ◽  
Chiral Molecules ◽  
One Pot ◽  
Complex Molecules ◽  
Chiral Complex ◽  
Enamine Catalysis ◽  
Daunting Challenge

<p></p><p>Chiral molecules with their defined 3-D structures are of paramount importance for the study of chemical biology and drug discovery. Having rich structural diversity and unique stereoisomerism, chiral molecules offer a large chemical space that can be explored for the design of new therapeutic agents.<sup>1</sup> In practice, chiral architectures are usually prepared from organometallic and organocatalytic processes where a transition metal or an organocatalyst is tailor-made for a desired reaction. As a result, developing a method that enables rapid assembly of chiral complex molecules under a metal- and organocatalyst-free condition represents a daunting challenge. Here we developed a straightforward one-pot procedure to create a chiral 3-D structure from 2-D structures and an amino acid without any chiral catalyst. The center of this research is the design of a <a>special chiral spiroimidazolidinone cyclohexadienone intermediate</a>, a merger of a chiral reactive substrate with multiple nucleophillic/electrophillic sites and a transient organocatalyst. <a>This unique substrate-catalyst (“sub-catalyst”) dual role of the intermediate was displayed in its aza-Michael/Michael cascade reaction with an </a>α,β-unsaturated aldehyde under an iminium/enamine catalysis. <a>The enhanced co-ordinational proximity of the chiral substrate and catalyst</a> in the transition state resulted in a substantial steric discrimination and an excellent overall diastereoselectivity. Aza-tricylic molecules with six contiguous stereocenters were assembled from <i>N</i>-alkylated aminophenols, α,β-unsaturated aldehydes and chiral α-amino acids under a hidden “sub-catalysis” where the strategically produced “sub-catalyst” does not present in initial components of the reaction. The success of this methodology will pave the way for many efficient preparations of chiral complex molecules.</p><br><p></p>

Stereoselective organocatalytic oxidation of alcohols to enals: a homologation method to prepare polyenes

2016 ◽  
Vol 52 (17) ◽  
pp. 3532-3535 ◽  
Author(s):  
Xiaobei Chen ◽  
Yinan Zhang ◽  
Huixin Wan ◽  
Wei Wang ◽  
Shilei Zhang
Keyword(s):  
Oxidation Of Alcohols ◽  
Enamine Catalysis ◽  
Novel Method

A novel method for organocatalytic oxidation through oxidative enamine catalysis was developed with excellent compatibility for the direct syntheses of enals from simple saturated alcohols.

Enantioselective Formal [3+3] Cycloadditions of Ketones and Cyclic 1-Azadienes by Cascade Enamine-Enamine Catalysis

2015 ◽  
Vol 21 (8) ◽  
pp. 3443-3448 ◽  
Author(s):  
Xiao-Long He ◽  
You-Cai Xiao ◽  
Wei Du ◽  
Ying-Chun Chen
Keyword(s):  
Enamine Catalysis

Enamine Catalysis with Photoredox Catalysis

2012 ◽  
pp. 1
Author(s):  
Z. -Y. Han ◽  
C. Wang ◽  
L. -Z. Gong
Keyword(s):  
Photoredox Catalysis ◽  
Enamine Catalysis

scholarly journals Ugi reaction-derived prolyl peptide catalysts grafted on the renewable polymer polyfurfuryl alcohol for applications in heterogeneous enamine catalysis

2019 ◽  
Vol 15 ◽  
pp. 1210-1216 ◽  
Author(s):  
Alexander F de la Torre ◽  
Gabriel S Scatena ◽  
Oscar Valdés ◽  
Daniel G Rivera ◽  
Márcio W Paixão
Keyword(s):  
Multicomponent Reactions ◽  
Supported Catalysts ◽  
Ugi Reaction ◽  
Multicomponent Synthesis ◽  
Polyfurfuryl Alcohol ◽  
Peptide Catalysts ◽  
Asymmetric Michael Addition ◽  
Enamine Catalysis ◽  
Work Supports ◽  
Peptide Catalyst

The multicomponent synthesis of prolyl pseudo-peptide catalysts using the Ugi reaction with furfurylamines or isocyanides is described. The incorporation of such a polymerizable furan handle enabled the subsequent polymerization of the peptide catalyst with furfuryl alcohol, thus rendering polyfurfuryl alcohol-supported catalysts for applications in heterogeneous enamine catalysis. The utilization of the polymer-supported catalysts in both batch and continuous-flow organocatalytic procedures proved moderate catalytic efficacy and enantioselectivity, but excellent diastereoselectivity in the asymmetric Michael addition of n-butanal to β-nitrostyrene that was used as a model reaction. This work supports the potential of multicomponent reactions towards the assembly of catalysts and their simultaneous functionalization for immobilization.

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