Issue 10, 2022

Palladium-catalyzed regio- and chemoselective double-alkoxycarbonylation of 1,3-diynes: a computational study

Abstract

The palladium-catalyzed double-alkoxycarbonylation of 1,3-diynes provides an efficient approach for the selective synthesis of 1,2,3,4-tetrasubstituted conjugated dienes. In this report, density functional theory calculations have been performed to elucidate the detailed reaction mechanism and the origins of the regio- and chemoselectivities. The computations show that the overall reaction involves two consecutive catalytic cycles with the same reaction mechanism. The catalytic cycle begins with the hydropalladation of the C–C triple bond via the N–H proton shuttle transfer to give a Pd–alkenyl intermediate, from which the CO insertion into the Pd–C bond occurs to form a Pd–acyl complex. The final product can be generated through alcoholysis with the assistance of the 2-pyridyl ring. The hydropalladation constitutes the rate- and regioselectivity-determining step. The computations very well reproduced the experimentally observed selectivity. The conjugated effect of the alkynyl group and the C–H⋯π interactions were identified as the key factors controlling the regioselectivity. The chemoselectivity between the alkoxycarbonylation of the C–C double and triple bonds was rationalized in terms of the steric repulsion and the interaction between the Pd center and C–C double bond.

Graphical abstract: Palladium-catalyzed regio- and chemoselective double-alkoxycarbonylation of 1,3-diynes: a computational study

Supplementary files

Article information

Article type
Research Article
Submitted
24 Jan 2022
Accepted
01 Apr 2022
First published
04 Apr 2022

Org. Chem. Front., 2022,9, 2697-2707

Palladium-catalyzed regio- and chemoselective double-alkoxycarbonylation of 1,3-diynes: a computational study

J. Yang, D. Kong, H. Wu, Z. Shen, H. Zou, W. Zhao and G. Huang, Org. Chem. Front., 2022, 9, 2697 DOI: 10.1039/D2QO00122E

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