Cobalt-Catalyzed Intermolecular C–H Amidation of Unactivated Alkanes
| Autor: | Sukbok Chang, Jeonghyo Lee, Seongho Jin, Soon Hyeok Hong, Dong-Wook Kim |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
Steric effects High interest Intermolecular force chemistry.chemical_element General Chemistry 010402 general chemistry Hydrogen atom abstraction 01 natural sciences Biochemistry Combinatorial chemistry Catalysis 0104 chemical sciences Colloid and Surface Chemistry Hydrocarbon chemistry Selectivity Cobalt |
| Zdroj: | Journal of the American Chemical Society. 143:5191-5200 |
| ISSN: | 1520-5126 0002-7863 |
| Popis: | Alkanes are an abundant and inexpensive source of hydrocarbons; thus, development of new methods to convert the hydrocarbon feedstocks to value-added chemicals is of high interest. However, it is challenging to achieve such transformation in a direct and selective manner mainly due to the intrinsic inertness of their C-H bonds. We herein report a tailored Cp*Co(III)(LX)-catalyzed efficient and site-selective intermolecular amidation of unactivated hydrocarbons including light alkanes. Electronic modulation of the cobalt complexes led to the enhanced amidation efficiency, and these effects were theoretically rationalized by the FMO analysis of presupposed cobalt nitrenoid species. Under the current cobalt protocol, a secondary C-H bond selectivity was observed in various nonactivated alkanes to reverse the intrinsic tertiary preference, which is attributed to the steric demands of the cobalt system that imposes difficulties in accessing tertiary C-H bonds. Experimental and computational studies suggested that the putative triplet Co nitrenoids are transferred to the C-H bonds of alkanes via a radical-like hydrogen abstraction pathway. |
| Databáze: | OpenAIRE |
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