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Sharma M, Perkins AM, Awoyemi RF, Schmittou AN, Raju S, Pierce BS, Donnadieu B, Wipf DO, Stokes SL, Emerson JP. Three water-soluble copper(II) N-heterocyclic carbene complexes: toward copper-catalyzed ketone reduction under sustainable conditions. Dalton Trans 2024. [PMID: 38247368 DOI: 10.1039/d3dt03406b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
A series of tridentate copper(II) N-heterocyclic carbene (NHC) complexes with imidazole, benzimidazole, and 5,6-dimethylbenzimidazole azole rings were synthesized and comprehensively characterized via X-ray crystallography, ESI-MS, cyclic voltammetry, and UV-Vis and EPR spectroscopic studies. These complexes were then utilized for the optimization of ketone reduction under sustainable conditions using 2-acetylpyridine and phenylsilane. The relationships between product formation, temperature, reaction time, and catalyst loading for the hydrogenation reactions are covered in detail. Reduction of eighteen different aliphatic, cyclic, and aromatic ketones were demonstrated, which were compatible to produce the corresponding products in moderate to good yields. These systems were used to develop related DNA-hybrid catalytic systems, but only supported weak enantioselectivity. Further thermodynamic experiments showed Cu-NHC complexes did not demonstrate specific binding to DNA, which is consistent with their limited selectivity.
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Affiliation(s)
- Mitu Sharma
- Department of Chemistry, Mississippi State University, Mississippi State, MS, USA.
| | - Amanda M Perkins
- Department of Chemistry, Mississippi State University, Mississippi State, MS, USA.
| | - Raymond Femi Awoyemi
- Department of Chemistry, Mississippi State University, Mississippi State, MS, USA.
| | - Allison N Schmittou
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, AL, USA
| | - Selvam Raju
- Department of Chemistry, Mississippi State University, Mississippi State, MS, USA.
| | - Brad S Pierce
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, AL, USA
| | - Bruno Donnadieu
- Department of Chemistry, Mississippi State University, Mississippi State, MS, USA.
| | - David O Wipf
- Department of Chemistry, Mississippi State University, Mississippi State, MS, USA.
| | - Sean L Stokes
- Department of Chemistry, Mississippi State University, Mississippi State, MS, USA.
| | - Joseph P Emerson
- Department of Chemistry, Mississippi State University, Mississippi State, MS, USA.
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Sharma M, Adhikari B, Awoyemi RF, Perkins AM, Duckworth AK, Donnadieu B, Wipf DO, Stokes SL, Emerson JP. Copper(II) NHC Catalyst for the Formation of Phenol from Arylboronic Acid. CHEMISTRY (BASEL, SWITZERLAND) 2022; 4:560-575. [PMID: 38031556 PMCID: PMC10686634 DOI: 10.3390/chemistry4020040] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Abstract
Arylboronic acids are commonly used in modern organic chemistry to form new C-C and C-heteroatom bonds. These activated organic synthons show reactivity with heteroatoms in a range of substrates under ambient oxidative conditions. This broad reactivity has limited their use in protic, renewable solvents like water, ethanol, and methanol. Here, we report our efforts to study and optimize the activation of arylboronic acids by a copper(II) N-heterocyclic carbene (NHC) complex in aqueous solution and in a range of alcohols to generate phenol and aryl ethers, respectively. The optimized reactivity showcases the ability to make targeted C-O bonds, but also identifies conditions where water and alcohol activation could be limiting for C-C and C-heteroatom bond-forming reactions. This copper(II) complex shows strong reactivity toward arylboronic acid activation in aqueous medium at ambient temperature. The relationship between product formation and temperature and catalyst loading are described. Additionally, the effects of buffer, pH, base, and co-solvent are explored with respect to phenol and ether generation reactions. Characterization of the new copper(II) NCN-pincer complex by X-ray crystallography, HR-MS, cyclic voltammetry, FT-IR and UV-Vis spectral studies is reported.
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Affiliation(s)
- Mitu Sharma
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762-9573, USA
| | - Bhupendra Adhikari
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762-9573, USA
| | - Raymond Femi Awoyemi
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762-9573, USA
| | - Amanda M. Perkins
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762-9573, USA
| | - Alison K. Duckworth
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762-9573, USA
| | - Bruno Donnadieu
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762-9573, USA
| | - David O. Wipf
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762-9573, USA
| | - Sean L. Stokes
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762-9573, USA
| | - Joseph P. Emerson
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762-9573, USA
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Edmonds T, Guogang P, West T. The differential pulse anodic stripping voltammetry of copper and lead and their determination in EDTA extracts of soils with the mercury film glassy carbon electrode. Anal Chim Acta 1980. [DOI: 10.1016/s0003-2670(01)84346-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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