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Carboxylation Reactions with Carbon Dioxide Using N‐Heterocyclic Carbene‐Copper Catalysts
Author(s) -
Zhang Liang,
Li Zhenghua,
Takimoto Masanori,
Hou Zhaomin
Publication year - 2020
Publication title -
the chemical record
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.61
H-Index - 78
eISSN - 1528-0691
pISSN - 1527-8999
DOI - 10.1002/tcr.201900060
Subject(s) - carboxylation , chemistry , carbene , catalysis , functional group , organic chemistry , hydrosilylation , alkyne , steric effects , combinatorial chemistry , polymer
The development of versatile catalyst systems and new transformations for the utilization of carbon dioxide (CO 2 ) is of great interest and significance. This Personal Account reviews our studies on the exploration of the reactions of CO 2 with various substrates by the use of N‐heterocyclic carbene (NHC)‐copper catalysts. The carboxylation of organoboron compounds gave access to a wide range of carboxylic acids with excellent functional group tolerance. The C−H bond carboxylation with CO 2 emerged as a straightforward protocol for the preparation of a series of aromatic carboxylic esters and butenoates from simple substrates. The hydrosilylation of CO 2 with hydrosilanes provided an efficient method for the synthesis of silyl formate on gram scale. The hydrogenative or alkylative carboxylation of alkynes, ynamides and allenamides yielded useful α,β ‐unsaturated carboxylic acids and α,β ‐dehydro amino acid esters. The boracarboxylation of alkynes or aldehydes afforded the novel lithium cyclic boralactone or boracarbonate products, respectively. The NHC‐copper catalysts generally featured excellent functional group compatibility, broad substrate scope, high efficiency, and high regio‐ and stereoselectivity. The unique electronic and steric properties of the NHC‐copper units also enabled the isolation and structural characterization of some key intermediates for better understanding of the catalytic reaction mechanisms.