Juliani Costa Ivanna G R, Batista Patrick R, T de Oliveira Marcelo, Braga Ataualpa A C
Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, São Paulo, São Paulo 05508-000, Brazil.
Institute of Chemistry, University of Campinas, Monteiro Lobato, 270, Cidade Universitaria,, Campinas, Sao Paulo 13083-862, Brazil.
ACS Org Inorg Au. 2025 Mar 11;5(3):181-193. doi: 10.1021/acsorginorgau.5c00004. eCollection 2025 Jun 4.
The present study employs DFT calculations and the independent gradient model (IGM) approach to investigate a mechanism study of the hydroboration reaction of internal alkynes catalyzed by Ag-(I)-IMes and Cu-(I)-IMes complexes. A detailed analysis of the mechanism's steps revealed that Cu-(I)-IMes exhibits superior efficiency, showing a more favorable energy pathway than Ag-(I)-IMes. The IGM method was crucial for quantifying molecular interactions, highlighting essential differences in binding forces between catalysts and substrates throughout the catalytic steps. For Cu-(I)-IMes, the migratory insertion step (TS1) demonstrated a barrier 2.5 times lower than its Ag-(I)-IMes counterpart. Additionally, the protonation step (TS2) exhibited lower energy for Cu-(I)-IMes compared to Ag-(I)-IMes, indicating a more efficient formation of the desired β-product. The results also suggest that Cu-(I)-IMes operates on a more efficient pathway, with lower energy for the catalytic cycle. These findings, coupled with detailed analyses of molecular interactions using the IGM method, provide an enhanced understanding of the reaction mechanism, highlighting the promising efficacy of Cu-(I)-IMes as a catalyst in hydroboration reactions.
本研究采用密度泛函理论（DFT）计算和独立梯度模型（IGM）方法，对由Ag-(I)-IMes和Cu-(I)-IMes配合物催化的内炔硼氢化反应机理进行研究。对该机理步骤的详细分析表明，Cu-(I)-IMes表现出更高的效率，其能量路径比Ag-(I)-IMes更有利。IGM方法对于量化分子间相互作用至关重要，突出了在整个催化步骤中催化剂与底物之间结合力的本质差异。对于Cu-(I)-IMes，迁移插入步骤（TS1）的势垒比其对应的Ag-(I)-IMes低2.5倍。此外，与Ag-(I)-IMes相比，Cu-(I)-IMes的质子化步骤（TS2）能量更低，表明所需β-产物的形成更有效。结果还表明，Cu-(I)-IMes通过更有效的路径运行，催化循环的能量更低。这些发现，结合使用IGM方法对分子间相互作用的详细分析，加深了对反应机理的理解，突出了Cu-(I)-IMes作为硼氢化反应催化剂的潜在效能。
