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1,3,5-Triaryl 2-pyridylidene: base-promoted generation and complexation
Kazuhiro Hata1, Yasutomo Segawa, Kenichiro Itami
1Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya 464-8602, Japan.
Chemical Communications (Cambridge, England)
|May 30, 2012
Summary
Researchers generated sterically hindered 1,3,5-triaryl 2-pyridylidenes from pyridinium salts. These reactive carbenes were trapped to form pyridinethiones and gold complexes, demonstrating their versatility.
Area of Science:
- Organic Chemistry
- Carbene Chemistry
Background:
- 1,3,5-Triaryl 2-pyridylidenes are sterically hindered carbene species.
- Generation of such carbenes from readily available pyridinium salts is synthetically valuable.
Purpose of the Study:
- To report a novel base-promoted method for generating sterically hindered 1,3,5-triaryl 2-pyridylidenes.
- To explore the reactivity of these generated 2-pyridylidenes through trapping experiments.
Main Methods:
- Base-promoted deprotonation of pyridinium salts to generate 2-pyridylidene intermediates.
- Trapping of the generated 2-pyridylidene with elemental sulfur (S(8)) and a gold(I) complex (Me(2)SAuCl).
Main Results:
- Successful generation of sterically hindered 1,3,5-triaryl 2-pyridylidenes.
- Formation of 2-pyridinethione and a 2-pyridylidene-gold(I) complex via trapping reactions.
- Observation of carbene rearrangement to pyrido[1,2-a]indole, indicating high carbene reactivity.
Conclusions:
- A new route to sterically hindered 2-pyridylidenes has been established.
- The generated 2-pyridylidenes exhibit high reactivity, enabling formation of diverse products.
- This work expands the synthetic utility of pyridylidene carbenes.
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