2016 Fiscal Year Research-status Report
Dual Catalysis with Photoredox Catalysts for Organic Transformations Mediated by Single-Electron Transfer Processes
| Project/Area Number |
16K17865
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| Research Institution | The University of Tokyo |
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Principal Investigator |
ユー ウージン 東京大学, 大学院理学系研究科(理学部), 特任助教 (70626077)
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| Project Period (FY) |
2016-04-01 – 2018-03-31
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| Keywords | carbon dioxide / C-H functionalization / copper / silicon |
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| Outline of Annual Research Achievements |
The proposed research was based on the concept of activation of organo- and transition metal catalysts by single-electron transfers (SET) mediated by light-induced photoredox catalysts. However, during the research period, the popularity of coupling photoredox catalysts with other catalytic systems grown significantly, and we felt that we could not compete with other large international research groups. As such, we decided to focus on developing new synthetic methods utilizing carbon dioxide.
In that vein, we have focused on utilizing carbon dioxide as a sustainable source of a carbon feedstock to prepare various organic molecules of biological interests. Since carbon dioxide is such a simple building block, our overall research goal was to develop multi-component coupling/step reactions with carbon dioxide. In light of the importance of phthalides in medicinal and agricultural sciences, we developed a new protocol that combined carbon-hydrogen bond activation with a carboxylation process to convert benzyl alcohols to phthalides. We found that a wide range of functional groups was tolerated under our reaction conditions, and that we could apply our methodology for the preparation of various natural products.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
The funded research was based on the desire to utilize visible light as an alternative energy source to mediate chemical reactions, and that we did not focus on this topic based on the current international research trend. As such, there was no progress for the funded research.
On the other hand, we have redirected the resources provided by the research grant monies to develop new carboxylation reactions. The conversion of carbon dioxide, a greenhouse gas, into useful organic compounds is an important goal from both an academic and industrial prospective, and we found made significant progress in this field. As such, we can state the research progress in developing organic transformations with carbon dioxide has advanced quite well, and we anticipate further developments in this field.
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| Strategy for Future Research Activity |
We plan to investigate further the use of carbon dioxide as a building block in organic synthesis by developing new synthetic methods and catalysts. Based on our previous work in synthesizing phthalides (5-membered lactones), we wish to expand upon this chemistry further to prepare a wide array of lactones using the approach of C-H activation and carboxylation chemistry. To achieve this, we will need to develop new catalysts that will enable the C-H activation of a wide variety of alcohols, and find new catalysts that will facilitate the carboxylation reaction of the reaction intermediates.
We will also investigate other kinds of multi-component coupling reactions that incorporate carbon dioxide. We have some preliminary data that suggest that we can synthesize trifluoromethylated carboxylic acids via fluorocarboxylation of 1,1-difluoroalkenes, and we are working towards the completion of this project.
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