The multicarbonyl manganese pincer complex-catalyzed α-methylation reaction is studied. In this theoretical work, an unprecedented carbonylic-carbon-centered mechanism is discovered. That is, the catalytic center is on the carbonyl ligand instead of the metal atom, such as the common aromatization/dearomatization metal–ligand cooperation mechanism. Further, the origins of chemoselectivity of enone hydrogenation are addressed with the $DEL-type NBO analyses. With a manganese pincer catalyst, the donor–acceptor electron transfer is found from the C═C bond to the C═O antibond, which can be regarded as the original driving force for the enone C═C hydrogenation. In contrast, the Noyori-type RuH₂(diphosphine)(diamine) catalysts favor the C═O hydrogenation, where the driving force is the donor–acceptor interaction associated with the O···H–N hydrogen bond.

中文翻译：

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羰基碳为中心的催化α-甲基化机理

研究了多羰基锰钳络合物催化的α-甲基化反应。在这项理论工作中，发现了前所未有的以羰基碳为中心的机制。也就是说，催化中心在羰基配体上而不是金属原子上，例如常见的芳构化/脱芳构化金属-配体协同机制。此外，烯酮氢化的化学选择性的起源通过 $DEL 型 NBO 分析得到解决。使用锰钳催化剂，发现供体-受体电子转移是从 C=C 键到 C=O 反键，这可以看作是烯酮 C=C 加氢的原始驱动力。相比之下，野依型 RuH ₂(二膦)(二胺)催化剂有利于C=O氢化，其中驱动力是与O···H-N氢键相关的供体-受体相互作用。