Reductive Carbonylation of Aryl Halides Employing a Two-Chamber Reactor: A Protocol for the Synthesis of Aryl Aldehydes Including 13C- and D-Isotope Labeling
摘要:
A protocol has been developed for conducting the palladium-catalyzed reductive carbonylation of aryl iodides and bromides using 9-methylfluorene-9-carbonyl chloride (COgen) as a source of externally delivered carbon monoxide in a sealed two-chamber system (COware), and potassium formate as the in situ hydride source. The method is tolerant to a wide number Of functional groups positioned on the aromatic ring, and it can be exploited for the isotope labeling of the aldehyde group. Hence, reductive carbonylations run with (13)COgen provide a facile access to C-13-labeled aromatic aldehydes, whereas with DCO2K, the aldehyde is specifically labeled with deuterium. Two examples of double isotopic labeling are also demonstrated. Finally, the method was applied to the specific carbon-13 labeling of the beta-amyloid binding compound, florbetaben.
Mechanistic Studies on the Reversible Hydrogenation of Carbon Dioxide Catalyzed by an Ir-PNP Complex
作者:Ryo Tanaka、Makoto Yamashita、Lung Wa Chung、Keiji Morokuma、Kyoko Nozaki
DOI:10.1021/om2010172
日期:2011.12.26
The PNP-ligated iridium(III) trihydride complex 1 exhibited the highest catalytic activity for hydrogenation of carbondioxide in aqueous KOH. The catalytic hydrogenation can be tuned to be a reversible process with the same catalyst at the expense of the activity, when triethanolamine was used as a base. Theoretical studies on the hydrogenation of carbondioxide using DFT calculations suggested two competing
Mechanistic Insight through Factors Controlling Effective Hydrogenation of CO<sub>2</sub> Catalyzed by Bioinspired Proton-Responsive Iridium(III) Complexes
作者:Wan-Hui Wang、James T. Muckerman、Etsuko Fujita、Yuichiro Himeda
DOI:10.1021/cs400172j
日期:2013.5.3
studies of the involvement of a water molecule in the rate-determining heterolysis of H2 and accelerated proton transfer by formation of a water bridge in CO2 hydrogenationcatalyzed by bioinspired complexes bearing a pendent base. Furthermore, contrary to expectations, a more significant enhancement of the catalyticactivity was observed from electron donation by the ligand than on the number of the active
A New Approach to the Reduction of Carbon Dioxide: CO<sub>2</sub> Reduction to Formate by Transfer Hydrogenation in <i>i</i>PrOH
作者:Sergio Sanz、Miriam Benítez、Eduardo Peris
DOI:10.1021/om900820x
日期:2010.1.11
A series of four Ir and Ru catalysts have been tested ill the reduction of CO2 to formate ill the presence of H-2. The iridium catalysts containing the basic NHC ligands were the ones to shou, better catalytic activities, achieving high TON values of up to 1800 TON. The unprecedented reduction of CO2 with iPrOH through a hydrogen transfer process is also described. TON values of up to 150 were obtained. Two other secondary alcohols, cyclohexanol and 1-phenylethanol, were also used as hydrogen sources for the reduction of carbon dioxide.
Reductive Carbonylation of Aryl Halides Employing a Two-Chamber Reactor: A Protocol for the Synthesis of Aryl Aldehydes Including <sup>13</sup>C- and D-Isotope Labeling
作者:Signe Korsager、Rolf H. Taaning、Anders T. Lindhardt、Troels Skrydstrup
DOI:10.1021/jo400741t
日期:2013.6.21
A protocol has been developed for conducting the palladium-catalyzed reductive carbonylation of aryl iodides and bromides using 9-methylfluorene-9-carbonyl chloride (COgen) as a source of externally delivered carbon monoxide in a sealed two-chamber system (COware), and potassium formate as the in situ hydride source. The method is tolerant to a wide number Of functional groups positioned on the aromatic ring, and it can be exploited for the isotope labeling of the aldehyde group. Hence, reductive carbonylations run with (13)COgen provide a facile access to C-13-labeled aromatic aldehydes, whereas with DCO2K, the aldehyde is specifically labeled with deuterium. Two examples of double isotopic labeling are also demonstrated. Finally, the method was applied to the specific carbon-13 labeling of the beta-amyloid binding compound, florbetaben.
Steric course of ketopantoate hydroxymethyltransferase in E. coli