Bimetallic synergism in alkyne silylformylation catalyzed by a cobalt-rhodium mixed-metal cluster
Bimetallic synergism in alkyne silylformylation catalyzed by a cobalt-rhodium mixed-metal cluster
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DOI：
10.1021/om060478x
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发表时间：
2006-07
期刊：
影响因子：
2.8
通讯作者：
N. Yoshikai;M. Yamanaka;I. Ojima;K. Morokuma;E. Nakamura
中科院分区：
文献类型：
--
作者：
N. Yoshikai;M. Yamanaka;I. Ojima;K. Morokuma;E. Nakamura
钴铑混合金属羰基络合物 Co2Rh2(CO)12 可有效催化炔烃甲酰基化，在 CC 三键上添加甲硅烷基和甲酰基。通过密度泛函计算阐明了该反应中的双金属协同作用。催化循环包括氢硅烷的氧化加成、炔插入、CO插入和还原消除。虽然主要的成键事件仅发生在铑中心，但钴也发挥着重要作用。它将金属簇固定在有机底物上，将氢化物配体暂时保留在金属中心上，并抑制氢化硅烷化，否则氢化硅烷化比甲硅烷基甲酰化更优选。 Rh和Co原子相互交换电子，产生独特的双金属反应途径，该途径与加氢甲酰化和氢化硅烷化的常规途径相关但又不同。
A cobalt−rhodium mixed-metal carbonyl complex Co2Rh2(CO)12 effects efficient catalytic silylformylation of an alkyne that adds silyl and formyl groups across the C−C triple bond. A bimetallic synergism in this reaction was elucidated with density functional calculations. The catalytic cycle consists of oxidative addition of hydrosilane, alkyne insertion, CO insertion, and reductive elimination. While major bond-forming events take place only at the rhodium center, the cobalt also plays an important role; it fixes the metal cluster on the organic substrate, keeps the hydride ligand temporarily on the metal center, and suppresses hydrosilylation, which would otherwise be preferred over the silylformylation. The Rh and Co atoms exchange electrons with each other, giving rise to a unique bimetallic reaction pathway that is related to but different from the conventional pathways of hydroformylation and hydrosilylation.