Controlling selectivity in the synthesis of Z-α,β-unsaturated amidines by tuning the N-sulfonyl group in a rhodium(II) catalyzed 1,2–H shift

Martin, M. L. and Boyer, A. (2021) Controlling selectivity in the synthesis of Z-α,β-unsaturated amidines by tuning the N-sulfonyl group in a rhodium(II) catalyzed 1,2–H shift. European Journal of Organic Chemistry, 2021(43), pp. 5857-5861. (doi: 10.1002/ejoc.202101235)

Abstract

N2-Sulfonyl-α-diazo amidines can be synthesized by the reaction of electron rich alkynyl amines with electron poor sulfonyl azides through 1,3-dipolar cycloadditions that proceed with perfect regioselectivity. In the presence of rhodium(II) carboxylate catalysts denitrogenation occurs to give the corresponding metallocarbenes. Then, there is a competition between 1,2–H shift and O-transfer from the sulfonyl group to the metallocarbene center. Using an electron poor nitrobenzenesulfonyl group and large carboxylate rhodium ligands gives complete selectivity for 1,2–H shift, forming α,β‑unsaturated-diazo amidines in high yield and excellent Z‑selectivity.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Boyer, Dr Alistair and Martin, Mr Matthew
• Authors: Martin, M. L., and Boyer, A.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: European Journal of Organic Chemistry
• Publisher: Wiley
• ISSN: 1434-193X
• ISSN (Online): 1099-0690
• Published Online: 21 October 2021
• Copyright Holders: Copyright © 2021 Wiley-VCH GmbH
• First Published: First published in European Journal of Organic Chemistry 2021(43): 5857-5861
• Publisher Policy: Reproduced in accordance with the publisher copyright policy