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Please login to access the full content or check if you have access via2.6.1.3 Carboxylation of Organoboron Reagents Catalyzed by N-Heterocyclic Carbene–Copper Complexes
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Nelson, D. J., Science of Synthesis: N-Heterocyclic Carbenes in Catalytic Organic Synthesis, (2016) 2, 284.
The carboxylation of boronic esters has been reported by Hou and co-workers. The reaction, catalyzed by [1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene]copper(I) chloride [CuCl(IPr)], which presumably forms Cu(Ot-Bu)(IPr) in situ, proceeds by transmetalation from boron to copper, followed by insertion of carbon dioxide into the Cu—C bond thus formed, as tested by stoichiometric experiments. Quite a wide range of aryl- and vinylboronic acid 2,2-dimethylpropane-1,3-diol esters 8 undergo reaction to form the corresponding carboxylic acids 9 (Scheme 4).[6] The same group reported subsequently that 9-borabicyclo[3.3.1]nonane compounds also undergo carboxylation successfully, allowing the development of a one-pot alkene hydroboration/carboxylation procedure.[7] Duong and co-workers have reported an analogous methodology for the carboxylation of allylboronates.[8]
Meeeee 8 Meeeeeeeeeeee ee Meeeeee Meee 8,8-Meeeeeeeeeeeeee-8,8-eeee Meeeee[8]
M8 | Meeee (%) | Mee |
---|---|---|
8-MeMM8M8 | 88 | [8] |
8-MeM8M8 | 88 | [8] |
8-MeM8M8 | 88 | [8] |
8-MM8M8 | 88 | [8] |
(M)-8-MeM8M8MM=MM | 88 | [8] |
(M)-8-MeMM8M8MM=MM | 88 | [8] |
8-eeeee | 88 | [8] |
8-eeeeeee | 88 | [8] |
Meeeeeeeeeee Meeeeeeee
Meeeeeeeee Meeee 8; Meeeeee Meeeeeeee:[8]
M 8 M eeee ee MMe-Me ee MMM (8.88 eM, 8.88 eeee) eee eeeee ee eeeeeee ee e eeeeeee eeee ee MeMe(MMe) (8.8 ee, 88 µeee) eee e eeeeeee eeeee 8 (8 eeee) eeeee M8 ee ee. MM8 eee eeeeeeeeee (eeeee e eeeeeee), eee eee eeeeeee eee eeee eeeeee ee 88 °M eee 88 e. Mee eeeeeee eee eeeeeeeee ee eeeeeeee ee 8 M ee MMe eee eee eeeeeee eeeee eee eeeeeeeee eeee MeMMe (8 ×). Mee eeeeeeee eeeeeee eeeeee eeee eeeeee eeee eeeee, eeeee (Me8MM8), eeeeeeee, eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee); eeeee: 88–88% (88 eeeeeeee).
References
[6] | Meeeee, M.; Meeeeeee, M.; Mee, M., Meeee. Meee. Mee. Me., (8888) 88, 8888. |
[7] | Meeeee, M.; Meeee, M.; Meeeeeee, M.; Mee, M., Meeee. Meee. Mee. Me., (8888) 88, 8888. |
[8] | Meeee, M. M.; Meeeeee, M. M.; Mee, M.-M.; Meeeeee, M. M., Mee. Meee., (8888) 88, 8888. |