2017 Fiscal Year Annual Research Report
Selective Synthetic Methodology Through the Control of Intramolecular Rearragements
| Project/Area Number |
16K17898
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| Research Institution | Kyoto University |
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Principal Investigator |
金 熙珍 京都大学, 工学研究科, 特定助教 (80754514)
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| Project Period (FY) |
2016-04-01 – 2018-03-31
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| Keywords | selective synthesis / intramolecular reaction / flow chemistry / microreactor / Fries rearrangement / Wittig rearrangement |
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| Outline of Annual Research Achievements |
We set the original purpose of the research on 2017: 1. the synthesis of biologically active molecules through the control of intramolecular rearrangement; 2. the expansion of the reaction scope to various rearrangement such as Wittig rearrangement. Among these, first purpose was achieved in 2016, thus, we focused on the second purpose in 2017.
Generally, sequential intramolecular rearrangements are often difficult to control at will, because they proceed quickly through multiple unstable intermediates having short life time. Thus, it is desirable to develop a novel methodology for controlling such serial reaction to obtain desired products with high selectivity. We set the reaction target to these tandem rearrangements of o-lithiated aryl benzyl ethers based on precise residence time control using flow microreactors. The tandem isomerizations of these intermediates includes H-Li exchange and [1,2]-Wittig rearrangement. In this research, we have demonstrated the flow-assisted complete control of tandem isomerizations. Under the optimized flow conditions based on the kinetic studies, three intermediates including aryl lithium, benzyl lithium, and lithium alkoxide could be selectively quenched to obtain the desired products.
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