Issue 8, 2017

Enantioselective catalytic β-amination through proton-coupled electron transfer followed by stereocontrolled radical–radical coupling

Abstract

A new mechanistic approach for the catalytic, enantioselective conjugate addition of nitrogen-based nucleophiles to acceptor-substituted alkenes is reported, which is based on a visible light induced and phosphate base promoted transfer of a single electron from a nitrogen nucleophile to a catalyst-bound acceptor-substituted alkene, followed by a stereocontrolled C–N bond formation through stereocontrolled radical–radical coupling. Specifically, N-aryl carbamates are added to the β-position of α,β-unsaturated 2-acyl imidazoles using a visible light activated photoredox mediator in combination with a chiral-at-rhodium Lewis acid catalyst and a weak phosphate base, affording new C–N bonds in a highly enantioselective fashion with enantioselectivities reaching up to 99% ee and >99 : 1 dr for a menthol-derived carbamate. As an application, the straightforward synthesis of a chiral β-amino acid ester derivative is demonstrated.

Graphical abstract: Enantioselective catalytic β-amination through proton-coupled electron transfer followed by stereocontrolled radical–radical coupling

Supplementary files

Article information

Article type
Edge Article
Submitted
05 May 2017
Accepted
15 Jun 2017
First published
15 Jun 2017
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2017,8, 5757-5763

Enantioselective catalytic β-amination through proton-coupled electron transfer followed by stereocontrolled radical–radical coupling

Z. Zhou, Y. Li, B. Han, L. Gong and E. Meggers, Chem. Sci., 2017, 8, 5757 DOI: 10.1039/C7SC02031G

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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