2018 Fiscal Year Annual Research Report
Design, Synthesis and Application of Novel Chiral Half-Sandwich Rare-Earth Complexes
| Project/Area Number |
18F18032
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| Research Institution | Institute of Physical and Chemical Research |
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Principal Investigator |
侯 召民 国立研究開発法人理化学研究所, 開拓研究本部, 主任研究員 (10261158)
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| Co-Investigator(Kenkyū-buntansha) |
ZHOU WEI 国立研究開発法人理化学研究所, 開拓研究本部, 外国人特別研究員
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| Project Period (FY) |
2018-04-25 – 2020-03-31
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| Keywords | aniline / alkyne / rare earth metal / scandium |
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| Outline of Annual Research Achievements |
Tertiary anilines which bearing allylic units are essential structural skeletons found in many fluorescent dyes, organic functional materials, pharmaceuticals and natural products. In principle, the catalytic benzylic C－H addition of 2-methyl tertiary anilines to internal alkynes is the most atom-efficient process for the synthesis of allylated tertiary anilines. However, the transition metal catalyzed benzylic C－H addition to internal alkynes is highly challenging and the reports in this area are rare which limited to special substrates, such as 8-methylquinolines. Therefore, the exploration of novel catalysts to realize the benzylic alkenylation of 2-methyl tertiary anilines is still in great demand.
Over the last year, we have developed the stereo- and reigioslective benzylic C－H addition of 2-methyl anilines to internal alkynes by employing a scandium complex for the first time. Both symmetrical and unsymmetrical internal alkynes were suitable in this reaction system and the desired trisubstituted alkene products could be achieved in good yields with high stereo- and regioselectivity. This work represents the first example of rare-earth metal catalyzed alkenylation reaction of benzylic C－H bonds with internal alkynes. Overall, we wish that this report will enrich the method of catalytic C－H bond functionalization and further enable the exploration of new catalytic system.
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| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
We strongly feel the reigioslective benzylic C－H addition of 2-methyl anilines to internal alkynes is of significant importance to the field of rare earth metal catalysis and synthetic methodology. Therefore, we would like to accomplish this project as soon as possible.
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| Strategy for Future Research Activity |
In the next year, our research plan is expected to develop a highly efficient strategy for the construction of a new family of chiral half-sandwich rare-earth alkyl complexes and employ them in the asymmetric benzylic C－H addition of 2-methyl anilines to internal alkynes.
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