2018 Fiscal Year Annual Research Report
Triphosphine ligand-enabled iron catalysis
Publicly Offered Research
| Project Area | Precise Formation of a Catalyst Having a Specified Field for Use in Extremely Difficult Substrate Conversion Reactions |
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| Project/Area Number |
18H04238
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| Research Institution | Institute of Physical and Chemical Research |
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Principal Investigator |
イリエシュ ラウレアン 国立研究開発法人理化学研究所, 環境資源科学研究センター, チームリーダー (40569951)
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| Project Period (FY) |
2018-04-01 – 2020-03-31
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| Keywords | 有機合成 |
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| Outline of Annual Research Achievements |
This project aims at the creation of a ligand that can control the reactivity of organoiron species and achieve an efficient and versatile iron catalyst for organic synthesis, surpassing precious metal catalysis. Thus, a triphosphine ligand is expected to stabilize organoiron species for catalytic reactions such as C-H bond functionalization.
During FY2018, we found that in the presence of an aluminum reagent as a base, an iron/triphosphine catalyst activates the C-H bond of aromatic ketones, following cyclization with internal alkynes. Attempts to use trimethylaluminum as the base just resulted in formation of an ortho-methylated product; by using a base generated in situ from 1 equiv of trimethylaluminum and 1 equiv of catechol, the reaction of an aromatic ketone with diphenylacetylene gave an indenol derivative in low yield. By using chloromethyl(trimethyl)silane as an additive, the yield was dramatically improved. Mechanistic studies suggested that this reagent transfers a methylsilyl group to iron to function as a base. A preliminary investigation of the reaction scope showed that a variety of symmetric diarylalkynes react well; notably, usymmetrical alkynes reacted with high regioselectivity.
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| Current Status of Research Progress |
Current Status of Research Progress
3: Progress in research has been slightly delayed.
Reason
During FY2018, I moved from the University of Tokyo to the RIKEN Center for Sustainable Resource Science, and during April-August I build up the laboratory from scratch. We started experiments from the end of August 2018, and people started joining the team during October-December. Thus, during FY2018 we could do research for less than 6 months, and therefore the development of the project was slower than expected.
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| Strategy for Future Research Activity |
During FY2019, I plan to studynd limitations for the aluminum-promoted, iron/triphosphine-catalyzed reaction of aromatic ketones with alkynes, and also gain mechanistic insights into the role of the aluminum reagent. Next, I plan to expand this reaction to other electrophiles; initial experiments showed that alkyl chlorides and boroesters react, albeit in low yield.
The combination of iron precatalyst, triphosphine ligand, and aluminum base will then be investigated for other reactions, for example cross-coupling or carbometalation-type reactions.
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Research Products
(15 results)
