2.6 C—H Functionalization Catalyzed by Low-Valent Cobalt
Book
Editor: Yoshikai, N.
Title: Base-Metal Catalysis 2
Print ISBN: 9783132455030; Online ISBN: 9783132455054; Book DOI: 10.1055/b000000440
1st edition © 2023 Thieme. All rights reserved.
Georg Thieme Verlag KG, Stuttgart
Subjects: Organic Chemistry;Chemical Reactions, Catalysis;Organometallic Chemistry;Laboratory Techniques, Stoichiometry
Science of Synthesis Reference Libraries
Parent publication
Title: Science of Synthesis
DOI: 10.1055/b-00000101
Series Editors: Fürstner, A. (Editor-in-Chief); Carreira, E. M.; Faul, M.; Kobayashi, S.; Koch, G.; Molander, G. A.; Nevado, C.; Trost, B. M.; You, S.-L.
Type: Multivolume Edition
Abstract
This review summarizes representative examples of catalytic C—H functionalization reactions mediated by low-valent cobalt complexes. Catalysts generated by the reduction of cobalt(II) or cobalt(III) precatalysts in the presence of appropriate supporting ligands have been demonstrated to promote a variety of alkylation, alkenylation, and arylation reactions of aromatic C(sp2)—H bonds, often with the assistance of directing groups. Well-defined cobalt(0) and cobalt(–I) complexes have also proved to catalyze some of these reactions. Low-valent cobalt complexes supported by bis(phosphinomethyl)pyridine, terpyridine, and diimine ligands have been identified as viable catalysts for the borylation of C(sp2)—H and C(sp3)—H bonds, where the cobalt catalysts exhibit unique site selectivity compared with well-established iridium catalysts. Other reactions such as 1,4-cobalt migration, hydroacylation, and C—H activation involving cobaltacyclopentene intermediates are also discussed.
Key words
base-metal catalysis - cobalt catalysis - C—H functionalization - C—H activation - C—H alkylation - C—H alkenylation - C—H arylation - C—H borylation - C—H carboxylation - hydroacylation - metal migration - directing groups- 14 Fallon BJ, Derat E, Amatore M, Aubert C, Chemla F, Ferreira F, Perez-Luna A, Petit M. J. Am. Chem. Soc. 2015; 137: 2448
- 16 Fallon BJ, Derat E, Amatore M, Aubert C, Chemla F, Ferreira F, Perez-Luna A, Petit M. Org. Lett. 2016; 18: 2292
- 19 Wang C.-S, Di Monaco S, Thai AN, Rahman MS, Pang BP, Wang C, Yoshikai N. J. Am. Chem. Soc. 2020; 142: 12878