Literature DB >> 24038872

Characterization of the key intermediates of carbene-catalyzed umpolung by NMR spectroscopy and X-ray diffraction: breslow intermediates, homoenolates, and azolium enolates.

Albrecht Berkessel1, Veera Reddy Yatham, Silvia Elfert, Jörg-M Neudörfl.   

Abstract

Caught in the act: Diamino enols, diamino dienols, azolium enolates, and azolium enols are postulated intermediates of the N-heterocyclic carbene catalyzed umpolung of aldehydes and enals. Several of these elusive reaction intermediates were generated with the saturated imidazolidin-2-ylidene SIPr (R=2,6-bis(2-propyl)phenyl) and characterized by NMR spectroscopy and X-ray crystallography.
Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Entities:  

Keywords:  NMR spectroscopy; X-ray diffraction; carbenes; reaction mechanisms; umpolung

Mesh：

Substances：

Year:  2013        PMID： 24038872     DOI： 10.1002/anie.201303107

Source DB:  PubMed          Journal:  Angew Chem Int Ed Engl        ISSN： 1433-7851            Impact factor:   15.336


  8 in total

1.  Radical [1,3] Rearrangements of Breslow Intermediates.

Authors:  Sefat Alwarsh; Yi Xu; Steven Y Qian; Matthias C McIntosh
Journal:  Angew Chem Int Ed Engl       Date:  2015-11-10       Impact factor: 15.336

2.  Critical Assessment of the Reducing Ability of Breslow-type Derivatives and Implications for Carbene-Catalyzed Radical Reactions*.

Authors:  Ludivine Delfau; Samantha Nichilo; Florian Molton; Julie Broggi; Eder Tomás-Mendivil; David Martin
Journal:  Angew Chem Int Ed Engl       Date:  2021-11-15       Impact factor: 16.823

3.  Rate and equilibrium constants for the addition of N-heterocyclic carbenes into benzaldehydes: a remarkable 2-substituent effect.

Authors:  Christopher J Collett; Richard S Massey; James E Taylor; Oliver R Maguire; AnnMarie C O'Donoghue; Andrew D Smith
Journal:  Angew Chem Int Ed Engl       Date:  2015-04-23       Impact factor: 15.336

4.  Rate and Equilibrium Constants for the Addition of N-Heterocyclic Carbenes into Benzaldehydes: A Remarkable 2-Substituent Effect.

Authors:  Christopher J Collett; Richard S Massey; James E Taylor; Oliver R Maguire; AnnMarie C O'Donoghue; Andrew D Smith
Journal:  Angew Chem Weinheim Bergstr Ger       Date:  2015-04-23

5.  A tandem dearomatization/rearomatization strategy: enantioselective N-heterocyclic carbene-catalyzed α-arylation.

Authors:  Zijun Wu; Jian Wang
Journal:  Chem Sci       Date:  2018-12-27       Impact factor: 9.825

6.  An Unexpected Inactivation of N-Heterocyclic Carbene Organic Catalyst by 1-Methylcyclopropylcarbaldehyde and 2,2,2-Trifluoroacetophenone.

Authors:  Yanling Chen; Jie Lv; Xuling Pan; Zhichao Jin
Journal:  Front Chem       Date:  2022-03-24       Impact factor: 5.221

7.  Formation of Breslow Intermediates from N-Heterocyclic Carbenes and Aldehydes Involves Autocatalysis by the Breslow Intermediate, and a Hemiacetal.

Authors:  Alina Wessels; Martin Klussmann; Martin Breugst; Nils E Schlörer; Albrecht Berkessel
Journal:  Angew Chem Int Ed Engl       Date:  2022-05-02       Impact factor: 16.823

8.  NHC-catalyzed cleavage of vicinal diketones and triketones followed by insertion of enones and ynones.

Authors:  Ken Takaki; Makoto Hino; Akira Ohno; Kimihiro Komeyama; Hiroto Yoshida; Hiroshi Fukuoka
Journal:  Beilstein J Org Chem       Date:  2017-08-30       Impact factor: 2.883
  8 in total

北京卡尤迪生物科技股份有限公司 © 2022-2023.