Direct Aroylation of Olefins through a Cobalt/Photoredox‐Catalyzed Decarboxylative and Dehydrogenative Coupling with α‐Oxo Acids
Direct Aroylation of Olefins through a Cobalt/Photoredox‐Catalyzed Decarboxylative and Dehydrogenative Coupling with α‐Oxo Acids
复制标题
通过钴/光氧化还原催化的α-含氧酸脱羧和脱氢偶联直接芳酰化烯烃
DOI：
10.1002/chem.202202781
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Tunge, Jon A.
中科院分区：
文献类型：
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作者：
Davies, Alex M.;D. Hernandez, Rafael;Tunge, Jon A.
已经开发了允许烯烃苯甲酰化的光氧化还原/钴双催化程序。在这里，光氧化还原催化剂影响α-酮酸的脱羧以形成苯甲酰基自由基。在将该自由基加成到苯乙烯之后，钴催化剂夺取H原子。从推定的氢化钴中间体中放出氢允许Heck样芳酰化，而不需要化学计量的氧化剂。机理研究表明，电子不同的苯乙烯导致弯曲的Hammett图，从而表明催化机制中产物决定步骤的变化。
A photoredox/cobalt dual catalytic procedure has been developed that allows benzoylation of olefins. Here the photoredox catalyst effects the decarboxylation of α‐ketoacids to form benzoyl radicals. After addition of this radical to styrenes, the cobalt catalyst abstracts a H‐atom. Hydrogen evolution from the putative cobalt hydride intermediate allows a Heck‐like aroylation without the need for a stoichiometric oxidant. Mechanistic studies reveal that electronically different styrenes lead to a curved Hammett plot, thus suggesting a change in product‐determining step in the catalytic mechanism.