Nickel-catalyzed asymmetric photoenolization/Mannich reaction of (2-alkylphenyl) ketones

Abstract

A diasteteo- and enantioselective photoenolization/Mannich (PEM) reaction of ortho-alkyl aromatic ketones with benzosulfonimides was established by utilizing a chiral N,Nʹ-dioxide/Ni(OTf)2 complex as the Lewis acid catalyst. It afforded a series of benzosulfonamides and the corresponding ring-closure products, and a reversal of diastereoselectivity was observed through epimerization of the benzosulfonamide products under continuous irradiation. On the basis of the control experiments, the role of the additive LiNTf2 in achieving high stereoselectivity was elucidated. This PEM reaction was proposed to undergo a direct nucleophilic addition mechanism rather than hetero-Diels–Alder/ring-opening sequence. A possible transition state model with photoenolization process was proposed to explain the origin of high level of stereoinduction.

Supplementary files

Article information

Article type
Edge Article
Submitted
16 May 2022
Accepted
21 Jun 2022
First published
22 Jun 2022
This article is Open Access

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

Chem. Sci., 2022, Accepted Manuscript

Nickel-catalyzed asymmetric photoenolization/Mannich reaction of (2-alkylphenyl) ketones

L. Yang, W. Li, L. Hou, T. Zhan, W. Cao, X. Liu and X. Feng, Chem. Sci., 2022, Accepted Manuscript , DOI: 10.1039/D2SC02721F

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, 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 commercial 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