Issue 17, 2018

E-Selective N-heterocyclic carbene-catalyzed reaction of aldehydes and butadienoates: effect of water and chloroform as the proton shuttle

Abstract

As we know, there are many reports on the reactions of the Breslow intermediate with electron-deficient alkenes or alkynes. However, the reactions with allenes are much less studied. In this study we observed that the N-heterocyclic carbene-catalyzed reaction of aldehydes and butadienoates afforded (E)-4-oxo-2-butenoates highly stereoselectively. It was observed that addition of water is critical for the observed high stereoselectivity. Mechanistic studies showed that the solvent chloroform acted as the proton shuttle involved in the formation of the Breslow intermediate, protonation, and deprotonation for this carbene-catalyzed reaction. Some key intermediates such as the Breslow intermediate and its monohydrate have been detected and characterized by MS studies, supporting the proposed mechanism.

Graphical abstract: E-Selective N-heterocyclic carbene-catalyzed reaction of aldehydes and butadienoates: effect of water and chloroform as the proton shuttle

Supplementary files

Article information

Article type
Research Article
Submitted
12 jún 2018
Accepted
11 júl 2018
First published
12 júl 2018

Org. Chem. Front., 2018,5, 2560-2567

E-Selective N-heterocyclic carbene-catalyzed reaction of aldehydes and butadienoates: effect of water and chloroform as the proton shuttle

D. Ma, Y. Song, C. Fu, F. Zhang, Y. Guo, X. Huang and S. Ma, Org. Chem. Front., 2018, 5, 2560 DOI: 10.1039/C8QO00579F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements