Laboratory for Computational Molecular Design, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
National Centre for Competence in Research - Catalysis (NCCR-Catalysis), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
Chemistry. 2022 Jul 20;28(41):e202200399. doi: 10.1002/chem.202200399. Epub 2022 Jun 10.
Group 9 metals, in particular Rh complexes with cyclopentadienyl ligands, are competent C-H activation catalysts. Recently, a CpRh -catalyzed reaction of alkenes with N-enoxyphthalimides showed divergent outcome based on the solvent, with carboamination favored in methanol and cyclopropanation in 2,2,2-trifluoroethanol (TFE). Here, we create selectivity and activity maps capable of unravelling the catalyst-solvent interplay on the outcome of these competing reactions by analyzing 42 cyclopentadienyl metal catalysts, Cp M (M=Co, Rh, Ir). These maps not only can be used to rationalize previously reported experimental results, but also capably predict the behavior of untested catalyst/solvent combinations as well as aid in identifying experimental protocols that simultaneously optimize both catalytic activity and selectivity (solutions in the Pareto front). In this regard, we demonstrate how and why the experimentally employed CpRh catalyst represents an ideal choice to invoke a solvent-induced change in reactivity. Additionally, the maps reveal the degree to which even perceived minor changes in the solvent (e. g., replacing methanol with ethanol) influence the ratio of carboamination and cyclopropanation products. Overall, the selectivity and activity maps presented here provide a generalizable tool to create global pictures of anticipated reaction outcome that can be used to develop new experimental protocols spanning metal, ligand, and solvent space.
第九族金属,特别是具有环戊二烯基配体的铑配合物,是有效的 C-H 活化催化剂。最近,烯烃与 N-氧代邻苯二甲酰亚胺的 CpRh 催化反应根据溶剂表现出不同的结果,在甲醇中有利于碳氨化,在 2,2,2-三氟乙醇(TFE)中有利于环丙烷化。在这里,我们通过分析 42 种环戊二烯基金属催化剂 CpM(M=Co、Rh、Ir)创建了选择性和活性图谱,这些图谱能够揭示催化剂-溶剂相互作用对这些竞争反应结果的影响。这些图谱不仅可以用于合理化以前报道的实验结果,还能够预测未经测试的催化剂/溶剂组合的行为,并有助于确定同时优化催化活性和选择性的实验方案(帕累托前沿中的解决方案)。在这方面,我们展示了为什么实验中使用的 CpRh 催化剂是引发反应性溶剂诱导变化的理想选择。此外,图谱还揭示了即使溶剂发生微小变化(例如,用乙醇代替甲醇),对碳氨化和环丙烷化产物比例的影响程度。总的来说,这里提出的选择性和活性图谱提供了一种可推广的工具,可以创建预期反应结果的全局图,用于开发跨越金属、配体和溶剂空间的新实验方案。