| Project/Area Number |
23K13739
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| Research Category |
Grant-in-Aid for Early-Career Scientists
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| Allocation Type | Multi-year Fund |
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| Review Section |
Basic Section 33020:Synthetic organic chemistry-related
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| Research Institution | Hokkaido University |
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Principal Investigator |
趙 強 北海道大学, 触媒科学研究所, 助教 (80933738)
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| Project Period (FY) |
2023-04-01 – 2025-03-31
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| Project Status |
Granted (Fiscal Year 2023)
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| Budget Amount *help |
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2024: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
Fiscal Year 2023: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
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| Keywords | Hydrogen atom transfer / HAT catalyst / Phosphine sulfide / Photocatalysis / Diastereoselectivity / Inversion / Radical reaction / chiral phosphoric acid / hydrogen atom transfer / radical reaction / photocatalysis / enantioselective |
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| Outline of Research at the Start |
本研究では有機リンラジカル種の分子設計を基盤とし、その水素原子移動（HAT）触媒としての力を引き出すことでラジカル反応を高度に制御する。有機ラジカル反応は広範に利用されている。しかし、有機ラジカルは高い反応性をもつ不安定な中間体として振る舞うため、反応性あるいは選択性を制御することは難しく、選択的ラジカル反応の開発は今もなお合成化学における未解決の課題の一つである。本研究では、HAT触媒として働くリン酸（III）分子を設計し、新たな有機ラジカル反応の高度制御法の開拓につなげることで、ラジカル種を用いる合成化学に革新をもたらす。
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| Outline of Annual Research Achievements |
A new series of secondary phosphine sulfide hydrogen atom transfer(HAT) catalysts have been successfully synthesized with high yields. A known photocatalytic reaction is used as model reaction to test its reactivity and selectivity. The newly synthesized secondary phosphine sulfide is indeed showing the hydrogen atom transfer catalytic ability. What`s more, to our delight, the diastereoselectivity of the model reaction has been inversed in the presence of the new HAT catalyst, compared with the well-known thiol HAT catalyst. We are now trying to understand the origin of the selectivity inversion by DFT calculations. Synthesis of chiral secondary phosphine sulfide HAT catalyst and investgation of its catalytic ability is underway in our lab.
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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
In this year, we synthesized a series of secondary phosphine oxides and secondary phosphine sulfides(SPS) with different substitutes according to the literature. Then, we tested its reactivity by a reported photocatalytic model reaction. The results showed that the secondary phosphine sulfide showing the hydrogen atom transfer ability. Meanwhile, the two substitutes of the SPS should both be aromatic group for keeping the catalytic ability. Thus, we have successfully demonstrated our proposal could be realized without a problem.
What`s more, we found the diastereoselectivity of the model reaction has been inversed in the presence of the SPS catalyst. We are now doing DFT calculations for the model reaction to make clear the exact reasons of the selectivity inversion.
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| Strategy for Future Research Activity |
In the next following year, we want to figure out the best structure of SPS compounds which shows the highest reactivity and selectivity by synthesizing a library of the compounds with considering the electronic and steric effect.
On the other hand, we want to understand the origin of the diastereoselectivity inversion though DFT calculation in cooperation with other DFT calculation specialists. The substrate scope will be studied and followed by a mechanistic investigation. In order to demonstrate the advantages of the newly synthesized secondary phosphine sulfide HAT catalyst, several synthetic transformations will be performed by using this new HAT catalyst.
Chiral SPS HAT catalysts will also be tried to test whether it can affect the enantioselectivity.
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