A series of cobalt POCOP pincer complexes with the formulas {2,6-(ⁱPr₂PO)₂-4-R′-C₆H₂}Co(CO)₂ (R′ = H (1a), NMe₂ (1b), OMe (1c), CO₂Me (1d)), {2,6-(Ph₂PO)₂C₆H₃}Co(CO)₂ (1e), and {2,6-(^tBu₂PO)₂C₆H₃}Co(CO) (2f) have been synthesized through C–H bond activation of the corresponding pincer ligands with Co₂(CO)₈. These complexes have been demonstrated to catalyze the hydrosilylation of PhCHO with (EtO)₃SiH, which exhibits an induction period and the decreasing reactivity order 1b > 1c > 1a > 1d > 1e. The catalytic protocol can be applied to various aldehydes with turnover numbers of up to 300. The CO ligands in the dicarbonyl complexes have been shown to exchange with ¹³CO at room temperature and partially dissociate from cobalt at high temperatures. Substitution of CO by tert-butyl isocyanide has been accomplished with 1a at 50–80 °C, resulting in the formation of {2,6-(ⁱPr₂PO)₂C₆H₃}Co(CN^tBu)(CO) (3a) and {2,6-(ⁱPr₂PO)₂C₆H₃}Co(CN^tBu)₂ (4a). The catalytic reactions are more efficient when they are carried out in an open system or if the catalysts are preactivated by the aldehydes. The structures of 1a–e, 3a, and 4a have been studied by X-ray crystallography.

中文翻译：

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通过配体C–H键与Co ₂（CO）_8的活化作用生成的POCOP钳形钴配合物：在开放系统与封闭系统中，醛的氢化硅烷化的催化活性

一系列具有式{2,6-（ⁱ Pr ₂ PO）₂ -4-R'-C ₆ H ₂ } Co（CO）₂（R'= H（1a），NMe ₂（1b），OMe（1c），CO ₂ Me（1d）），{2,6-（Ph ₂ PO）₂ C ₆ H ₃ } Co（CO）₂（1e）和{2,6-（^t Bu ₂ PO）₂ C ₆ H ₃ } Co（CO）（2f）是通过Co ₂（CO）₈相应的钳形配体的C–H键活化而合成的。这些配合物已被证明可以催化PhCHO与（EtO）₃ SiH的氢化硅烷化反应，该反应具有诱导期和递减顺序，依次为1b > 1c > 1a > 1d > 1e。该催化规程可以应用于周转数高达300的各种醛。二羰基络合物中的CO配体在室温下可与¹³ CO交换，并在高温下与钴部分解离。CO的取代由叔丁基异氰化物在50-80°C时用1a完成，导致形成{2,6-（ⁱ Pr ₂ PO）₂ C ₆ H ₃ } Co（CN ^t Bu）（CO）（3a）和{2，6-（ⁱ Pr ₂ PO）₂ C ₆ H ₃ } Co（CN ^t Bu）₂（4a）。当催化反应在开放系统中进行或催化剂被醛预活化时，催化反应会更有效。的结构1A - ë，3A，和已经通过X射线晶体学研究了图4a。