Issue 22, 2022

Unification of Ullmann and Kharasch coupling: acid promoted CuI catalysed C–N coupling protocols under ligand, base and solvent free conditions

Abstract

The copper catalysed C–N cross coupling reaction (Ullmann coupling) is one of the most extensively explored reactions in organic synthesis. Despite its notable advantages of being less toxic, and the use of inexpensive and abundant Cu metal, a continuous methodological development over the last century has been reported for a significant improvement of the general applicability of the reaction to a remarkable extent. Herein, we have demonstrated a significantly upgraded Ullmann reaction for C–N cross couplings of aryl/alkyl chlorides. The method works in completely opposite conditions and requires acid media instead of basic media. Moreover, the presented method is significantly influenced by the presence of various 3d transition metals, which work as a promoter and drastically reduce the reaction time. Furthermore, the reaction conditions significantly increase the catalytic activity of CuI, as well as the functional group tolerance of the reaction. Aliphatic amines (1° and 2°), benzylic amine, and anilines are well supported with arylchlorides. In conclusion, the presented method efficiently couples a wide variety of aryl/alkyl chlorides that are economical but difficult to activate, and the reaction works in the complete absence of ligand, base and solvent media.

Graphical abstract: Unification of Ullmann and Kharasch coupling: acid promoted CuI catalysed C–N coupling protocols under ligand, base and solvent free conditions

Supplementary files

Article information

Article type
Research Article
Submitted
18 Jul 2022
Accepted
17 Sep 2022
First published
19 Sep 2022

Org. Chem. Front., 2022,9, 6252-6258

Unification of Ullmann and Kharasch coupling: acid promoted CuI catalysed C–N coupling protocols under ligand, base and solvent free conditions

C. Sharma, A. K. Srivastava, D. Sharma and R. K. Joshi, Org. Chem. Front., 2022, 9, 6252 DOI: 10.1039/D2QO01080A

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