Direct synthesis of CH3COOH from CH4and CO2is an appealing approach for the utilization of two potent greenhouse gases that are notoriously difficult to activate. In this
Direct synthesis of CH3COOH from CH4and CO2is an appealing approach for the utilization of two potent greenhouse gases that are notoriously difficult to activate. In this
- PAR ID:
- 10414530
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 62
- Issue:
- 27
- ISSN:
- 1433-7851
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Communication , we report an integrated route to enable this reaction. Recognizing the thermodynamic stability of CO2, our strategy sought to first activate CO2to produce CO (through electrochemical CO2reduction) and O2(through water oxidation), followed by oxidative CH4carbonylation catalyzed by Rh single atom catalysts supported on zeolite. The net result was CH4carboxylation with 100 % atom economy. CH3COOH was obtained at a high selectivity (>80 %) and good yield (ca . 3.2 mmol g−1catin 3 h). Isotope labelling experiments confirmed that CH3COOH is produced through the coupling of CH4and CO2. This work represents the first successful integration of CO/O2production with oxidative carbonylation reaction. The result is expected to inspire more carboxylation reactions utilizing preactivated CO2that take advantage of both products from the reduction and oxidation processes, thus achieving high atom efficiency in the synthesis. -
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Abstract A low‐spin and mononuclear vanadium complex, (Menacnac)V(CO)(η2‐P≡C
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Abstract A low‐spin and mononuclear vanadium complex, (Menacnac)V(CO)(η2‐P≡C
t Bu) (2 ) (Menacnac−=[ArNC(CH3)]2CH, Ar=2,6‐i Pr2C6H3), was prepared upon treatment of the vanadium neopentylidyne complex (Menacnac)V≡Ct Bu(OTf) (1 ) with Na(OCP)(diox)2.5(diox=1,4‐dioxane), while the isoelectronic ate‐complex [Na(15‐crown‐5)]{([ArNC(CH2)]CH[C(CH3)NAr])V(CO)(η2‐P≡Ct Bu)} (4 ), was obtained via the reaction of Na(OCP)(diox)2.5and ([ArNC(CH2)]CH[C(CH3)NAr])V≡Ct Bu(OEt2) (3 ) in the presence of crown‐ether. Computational studies suggest that the P‐atom transfer proceeds by [2+2]‐cycloaddition of the P≡C bond across the V≡Ct Bu moiety, followed by a reductive decarbonylation to form the V−C≡O linkage. The nature of the electronic ground state in diamagnetic complexes,2 and4 , was further investigated both theoretically and experimentally, using a combination of density functional theory (DFT) calculations, UV/Vis and NMR spectroscopies, cyclic voltammetry, X‐ray absorption spectroscopy (XAS) measurements, and comparison of salient bond metrics derived from X‐ray single‐crystal structural characterization. In combination, these data are consistent with a low‐valent vanadium ion in complexes2 and4 . This study represents the first example of a metathesis reaction between the P‐atom of [PCO]−and an alkylidyne ligand. -
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