Synlett 2021; 32(07): 641-646
DOI: 10.1055/a-1306-3228
synpacts

C–O Bond Activation as a Strategy in Palladium-Catalyzed Cross-Coupling

Joseph Becica
,
We thank the Natural Sciences and Engineering Research Council (NSERC) of Canada, the New Frontiers in Research Fund (NFRF), and the University of Victoria for general operating funds, as well as the Canadian Foundation for Innovation (CFI) and British Columbia Knowledge Development Fund (BCKDF) for infrastructure funding.


Abstract

The activation of strong C–O bonds in cross-coupling catalysis can open up new oxygenate-based feedstocks and building blocks for complex-molecule synthesis. Although Ni catalysis has been the major focus for cross-coupling of carboxylate-based electrophiles, we recently demonstrated that palladium catalyzes not only difficult C–O oxidative additions but also Suzuki-type cross-couplings of alkenyl carboxylates under mild conditions. We propose that, depending on the reaction conditions, either a typical Pd(0)/(II) mechanism or a redox-neutral Pd(II)-only mechanism can operate. In the latter pathway, C–C bond formation occurs through carbopalladation of the alkene, and C–O cleavage by β-carboxyl elimination.

1 Introduction

2 A Mechanistic Challenge: Activating Strong C–O Bonds

3 Exploiting Vinylogy for C–Cl and C–O Oxidative Additions

4 An Alternative Mechanism for Efficient Cross-Coupling Catalysis

5 Conclusions and Outlook



Publication History

Received: 31 October 2020

Accepted: 09 November 2020

Accepted Manuscript online:
09 November 2020

Article published online:
02 December 2020

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