The electrochemical reduction of carbon dioxide can convert the greenhouse gas into value-added chemical products or fuels, which provides a promising strategy to address current energy and environmental issues. Incre...The electrochemical reduction of carbon dioxide can convert the greenhouse gas into value-added chemical products or fuels, which provides a promising strategy to address current energy and environmental issues. Increasing the selectivity for C2&C2+ products, particularly ethylene, remains an important goal in this field. We chose cuprous chloride as the catalyst precursor for electrochemical reduction of CO_2, which efficiently converted carbon dioxide to ethylene. CuCl powder exhibited a maximum ethylene faradaic efficiency (FE) of 37%,ethylene partial current density of 14.8 mA/cm^2, and selectivity of 57.5% for C2&C2+ products at-1.06 V (vs. reversible hydrogen electrode, RHE). Electron microcopy (TEM, SEM) and time-resolved ex situ X-ray diffraction (XRD) demonstrated that the catalyst was transformed gradually into a mixed phase of copper and cuprous oxide, with the morphological change into a cubic structure during reduction process. The presence of Cu^(1+) and the unique electrode morphology may simultaneously lead to the enhanced electrochemical activity.展开更多
With the growing urgency of potential catastrophic climate changes due to anthropogenic CO2 emissions,numerous efforts have been devoted to development of synthetic protocols using CO2 as a building block in organic r...With the growing urgency of potential catastrophic climate changes due to anthropogenic CO2 emissions,numerous efforts have been devoted to development of synthetic protocols using CO2 as a building block in organic reactions, but the general applicability to complex drug-like substrates remains a challenge.We develop a general protocol for scalable direct N-methylation of a wide-scope drug-like amines using CO2 and polymethylhydrosiloxane-a nontoxic, aerobically-stable hydrosilane considered as an industrial waste-via simple inorganic base catalysis. A rare application of the Sabatier principle in organic chemistry led to the discovery of cheap, nontoxic K3PO4 as an efficient catalyst. Preparations of a wide-scope drug-like amines with carbon-isotope label were also successfully achieved, enabling direct use of CO2 in studies of drug absorption, distribution, metabolism and excretion.展开更多
An efficient and practical synthetic protocol to synthesize nonsymmetrical aryl thioethers by nucleophilic aromatic substitution(S_NAr)reaction of nitroarenes by thiols with potassium phosphate as the catalyst is desc...An efficient and practical synthetic protocol to synthesize nonsymmetrical aryl thioethers by nucleophilic aromatic substitution(S_NAr)reaction of nitroarenes by thiols with potassium phosphate as the catalyst is described.Various moderate to strong electron-withdrawing functional groups are tolerated by the system to provide thioethers in a good to excellent yields.We also showed that the present method allows access to 3 drug examples in a short reaction time.Finally,mechanistic studies suggest that the reaction may form the classic Meisenheimer complex through a two-step additionelimination mechanism.展开更多
基金financially supported by Shell-CAS Frontier Sciences Program (No. PT48809) from Shell and start-up funding from Shanghai Tech University
文摘The electrochemical reduction of carbon dioxide can convert the greenhouse gas into value-added chemical products or fuels, which provides a promising strategy to address current energy and environmental issues. Increasing the selectivity for C2&C2+ products, particularly ethylene, remains an important goal in this field. We chose cuprous chloride as the catalyst precursor for electrochemical reduction of CO_2, which efficiently converted carbon dioxide to ethylene. CuCl powder exhibited a maximum ethylene faradaic efficiency (FE) of 37%,ethylene partial current density of 14.8 mA/cm^2, and selectivity of 57.5% for C2&C2+ products at-1.06 V (vs. reversible hydrogen electrode, RHE). Electron microcopy (TEM, SEM) and time-resolved ex situ X-ray diffraction (XRD) demonstrated that the catalyst was transformed gradually into a mixed phase of copper and cuprous oxide, with the morphological change into a cubic structure during reduction process. The presence of Cu^(1+) and the unique electrode morphology may simultaneously lead to the enhanced electrochemical activity.
基金supported by the National Natural Science Foundation of China(U1532135)
文摘With the growing urgency of potential catastrophic climate changes due to anthropogenic CO2 emissions,numerous efforts have been devoted to development of synthetic protocols using CO2 as a building block in organic reactions, but the general applicability to complex drug-like substrates remains a challenge.We develop a general protocol for scalable direct N-methylation of a wide-scope drug-like amines using CO2 and polymethylhydrosiloxane-a nontoxic, aerobically-stable hydrosilane considered as an industrial waste-via simple inorganic base catalysis. A rare application of the Sabatier principle in organic chemistry led to the discovery of cheap, nontoxic K3PO4 as an efficient catalyst. Preparations of a wide-scope drug-like amines with carbon-isotope label were also successfully achieved, enabling direct use of CO2 in studies of drug absorption, distribution, metabolism and excretion.
基金financial support by the National Natural Science Foundation of China (No.U1532135)
文摘An efficient and practical synthetic protocol to synthesize nonsymmetrical aryl thioethers by nucleophilic aromatic substitution(S_NAr)reaction of nitroarenes by thiols with potassium phosphate as the catalyst is described.Various moderate to strong electron-withdrawing functional groups are tolerated by the system to provide thioethers in a good to excellent yields.We also showed that the present method allows access to 3 drug examples in a short reaction time.Finally,mechanistic studies suggest that the reaction may form the classic Meisenheimer complex through a two-step additionelimination mechanism.
