Issue 14, 2023

Alkylation of amines with allylic alcohols and deep eutectic solvents as metal-free and green promoters

Abstract

A novel approach for the allylic alkylation of anilines, hydrazides, indole derivatives and additional interesting nucleophiles is described, which involves the direct use of a variety of allylic alcohols under very mild conditions, such as room temperature, and the use of sustainable deep eutectic solvents (DESs). The search for the optimum DES to be used in the reaction revealed that a simple mixture of choline chloride (ChCl) and lactic acid provides excellent results for a wide range of substrates with high isolated yields. This methodology represents a significant improvement compared to other procedures described in the literature, for which high temperatures, stronger reaction conditions or metal catalysts are usually required. In some cases, this protocol provides the first examples of trapping allylic carbocations with indole derivatives. In addition, challenging nucleophiles such as amides, carbamates, azides or sulfonamides, among others, have also been successfully used. All these features render this procedure an appealing and green alternative compared to other examples reported in the literature on the alkylation of amines by allylic alcohols. Preliminary mechanistic studies using unsymmetrically substituted alcohols support that the reaction could proceed via an SN1 pathway.

Graphical abstract: Alkylation of amines with allylic alcohols and deep eutectic solvents as metal-free and green promoters

Supplementary files

Article information

Article type
Paper
Submitted
29 Mar 2023
Accepted
23 May 2023
First published
01 Jun 2023
This article is Open Access
Creative Commons BY-NC license

Green Chem., 2023,25, 5601-5612

Alkylation of amines with allylic alcohols and deep eutectic solvents as metal-free and green promoters

S. Zárate-Roldán, M. C. Gimeno and R. P. Herrera, Green Chem., 2023, 25, 5601 DOI: 10.1039/D3GC01017A

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