103505-54-0Relevant articles and documents
A biomimetic copper water oxidation catalyst with low overpotential
Zhang, Teng,Wang, Cheng,Liu, Shubin,Wang, Jin-Liang,Lin, Wenbin
, p. 273 - 281 (2014)
Simply mixing a Cu(II) salt and 6,6′-dihydroxy-2,2′-bipyridine (H2L) in a basic aqueous solution afforded a highly active water oxidation catalyst (WOC). Cyclic voltammetry of the solution at pH = 12-14 shows irreversible catalytic current with an onset potential of ～0.8 V versus NHE. Catalytic oxygen evolution takes place in controlled potential electrolysis at a relatively low overpotential of 640 mV. Experimental and computational studies suggest that the L ligand participates in electron transfer processes to facilitate the oxidation of the Cu center to lead to an active WOC with low overpotential, akin to the use of the tyrosine radical by Photosystem II to oxidize the CaMn4 center for water oxidation.
Transfer hydrogenation in water via a ruthenium catalyst with OH groups near the metal center on a bipy scaffold
Nieto, Ismael,Livings, Michelle S.,Sacci, John B.,Reuther, Lauren E.,Zeller, Matthias,Papish, Elizabeth T.
, p. 6339 - 6342 (2011)
The new ligand 6,6′-dihydroxy-2,2′-bipyridyl (dhbp) was synthesized via its tautomer, and this provides an efficient route to novel metal complexes of dhbp. In ruthenium complexes of dhbp, these OH groups enhance water solubility and may play a role in aq
Reinvestigating catalytic alcohol dehydrogenation with an iridium dihydroxybipyridine catalyst
Brewster, Timothy P.,DeRegnaucourt, Alexa R.,Loadholt, Kylie H.,Papish, Elizabeth T.,Qu, Fengrui,Shrewsbury, Emily D.,Silprakob, Weerachai,Yao, Wenzhi
, p. 3656 - 3662 (2020/11/23)
The examined catalyst [Cp*Ir(H2O)(6,6′-dhbp)]2+ (1; 6,6′-dhbp = 6,6′-dihydroxy-2,2′-bipyridine) was reported in 2012 as a highly efficient (92% conversion) and selective catalyst for the conversion of benzyl alcohol to benzaldehyde as the sole product via acceptorless dehydrogenation. We report herein that the observed conversion and selectivity data are not accurate but may have resulted, in part, from other products being produced that are not easily detected. Specifically, benzoic acid is formed as a byproduct via the disproportionation of benzaldehyde, but at high temperatures, most of the benzoic acid produced is converted in situ to benzene and carbon dioxide. While we can explain the observed selectivity, we cannot explain the observed conversion to products. In our hands, we observed 15% conversion to products under the original conditions. Other alcohol substrates were also examined and gave lower conversion to products and decreased selectivity in comparison with the original report. Acceptorless alcohol dehydrogenation to generate aldehydes is a potentially transformative technology which can allow chemists to replace stoichiometric oxidants that produce waste with efficient catalysts that only generate H2 gas as a byproduct. Thus, clarification of the 2012 report to indicate what conditions can lead to high efficiency and selectivity is a worthy topic of discussion in the literature.
En Route to a Practical Primary Alcohol Deoxygenation
Dai, Xi-Jie,Li, Chao-Jun
, p. 5433 - 5440 (2016/05/19)
A long-standing scientific challenge in the field of alcohol deoxygenation has been direct catalytic sp3 C-O defunctionalization with high selectivity and efficiency, in the presence of other functionalities, such as free hydroxyl groups and amines widely present in biological molecules. Previously, the selectivity issue had been only addressed by classic multistep deoxygenation strategies with stoichiometric reagents. Herein, we propose a catalytic late-transition-metal-catalyzed redox design, on the basis of dehydrogenation/Wolff-Kishner (WK) reduction, to simultaneously tackle the challenges regarding step economy and selectivity. The early development of our hypothesis focuses on an iridium-catalyzed process efficient mainly with activated alcohols, which dictates harsh reaction conditions and thus limits its synthetic utility. Later, a significant advancement has been made on aliphatic primary alcohol deoxygenation by employing a ruthenium complex, with good functional group tolerance and exclusive selectivity under practical reaction conditions. Its synthetic utility is further illustrated by excellent efficiency as well as complete chemo- and regio-selectivity in both simple and complex molecular settings. Mechanistic discussion is also included with experimental supports. Overall, our current method successfully addresses the aforementioned challenges in the pertinent field, providing a practical redox-based approach to the direct sp3 C-O defunctionalization of aliphatic primary alcohols.
