Rhodium transition-metal-organic cooperative catalysis, which has been intensively studied by many chemists, represents a great success in C–H bond activation because of high efficiencies and selectivities. Typically, in the reaction mechanism of aldehyde and alkene catalyzed by Rh(I) complex and 2-amino-3-picoline, two kinds of metala-cyclic transition-metal complexes of (iminoacyl)rhodium(III)hydride and (iminoacyl)rhodium(III) alkyl are generally formed. The two complexes play an important role in the overall reaction, in which the Rh–C bond formations are involved. So it is meaningful to understand the strength of Rh–C bond, which can be measured by the homolytic bond dissociation enthalpies (BDEs). To this end, we first calculated 16 relative Rh–C BDEs of Tp′Rh(CNneopentyl)RH (Tp′ = hydridotris-(3,5-dimethylpyrazolyl)borate) by 19 density functional theory (DFT) methods. Furthermore, the 5 absolute Rh–C BDEs of Rh transition-metal complexes were also calculated. The results show that the B97D3 is the most accurate method to predict the relative and absolute Rh–C BDEs and the corresponding RMSE values are the smallest of 2.8 and 3.3 kcal/mol respectively. Therefore, the Rh–C BDEs of (iminoacyl)rhodium(III)hydride and (iminoacyl)rhodium(III)alkyl as well as the substituent effects were investigated by using the B97D3 method. The results indicated that the different substituents exhibit different effects on different types of Rh–C BDEs. In addition, the analysis including the natural bond orbital (NBO) as well as the energies of frontier orbitals were performed in order to further understand the essence of the Rh–C BDE change patterns.

许多化学家已经对铑过渡金属有机协同催化进行了深入研究，由于其高效率和高选择性，它在C–H键活化方面取得了巨大成功。通常，在Rh（I）配合物和2-氨基-3-甲基吡啶催化的醛与烯烃的反应机理中，氢化有（亚氨基酰基）铑（III）和（亚氨基酰基）铑的两种金属环过渡金属配合物。通常形成（III）烷基。在涉及Rh-C键形成的整个反应中，这两个络合物起着重要作用。因此，了解Rh-C键的强度是有意义的，可以通过均解键解离焓（BDE）进行测量。为此，我们首先计算了Tp'Rh（CNneopentyl）RH（Tp'= hydrtritris-（3，5-二甲基吡唑基）硼酸酯）通过19密度泛函理论（DFT）方法。此外，还计算了Rh过渡金属配合物的5种绝对Rh-C BDE。结果表明，B97D3是预测相对和绝对Rh–C BDE的最准确方法，相应的RMSE值分别为2.8和3.3 kcal / mol的最小值。因此，使用B97D3方法研究了（亚氨基酰基）铑（Ⅲ）氢化物和（亚氨基酰基）铑（Ⅲ）烷基的Rh-C BDE以及取代基的作用。结果表明，不同的取代基对不同类型的Rh–C BDEs表现出不同的作用。此外，还进行了包括自然键轨道（NBO）以及前沿轨道能量在内的分析，以进一步了解Rh–C BDE变化模式的本质。