Main Group Metal Mediated Hydrogenation Reactions and Catalysis

主族金属介导的氢化反应和催化

• 批准号: 490737079
• 负责人: Professor Dr. Stefan Grimme
• 金额: --
• 依托单位: Department of Chemistry
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/490737079?language=en
• 关键词: Main; Group; Metal; Mediated; Hydrogenation

The catalytic hydrogenation of unsaturated compounds using molecular dihydrogen (H2) as a clean reducing agent is one of the most important reactions in petroleum and chemical industry as well as organic synthesis. Most hydrogenation catalysts are derived from precious transition-metals that are often toxic and bio-incompatible. Recently, there is an increasing interest in more environment-friendly and cheaper alkaline and alkaline earth metal hydride catalysts that are usually found as dimers and even higher oligomers. Remarkable main-group-metal catalysts were reported for the hydrogenation of activated conjugated alkenes and even unactivated 1-alkenes as well as aldimines (PhHC=NR, R = tBu, iPr, Ph) under mild conditions. However, the detailed catalytic mechanism and especially the potential (metal) cooperative and (ligand) steric effects for understanding such catalytic systems often remain unclear. Very recently, together with Prof. Douglas W. Stephan's experimental group, we have demonstrated that dimeric alkaline metal complexes M2L2 (M = Li, Na, K; L = tBu2P, NCy2), K2L2 (L = N(SiMe3)2) and (C6H5CH2K)2 can facilitate reversible H2-activation and even reactions with a CO/H2 mixture to form new C-C chain and C-H bonds. Because of the complicated electronic structure of large metal hydride catalysts, additional interactions with unsaturated substrate and solvent molecules as well as potentially extensive exploration of reaction paths is required, detailed mechanistic studies of such catalytic hydrogenation reactions are computationally challenging. In this project, based on the efficient GFN2-xTB method (conformational and reaction paths exploration), dispersion-corrected low-cost DFT (fast structure screening), and high-level dispersion-corrected DFT methods (accurate structures and energies, highly correlated DLPNO-CCSD(T) as benchmark when necessary), a multi-level theoretical approach is adopted to efficiently explore various reaction paths, in order to identify the catalytic mechanisms in great detail. Through close interplay with experiment, this project aims at a deep mechanistic understanding of hydrogenation reactions catalyzed by main group metal catalysts as well as a rational design of environment-friendly and cheap new-generation hydrogenation catalysts.

使用分子二氢（H2）作为清洁还原剂的不饱和化合物的催化氢化是石油和化学工业中最重要的反应之一，以及有机合成。大多数氢化催化剂都是从通常有毒且不兼容的宝贵过渡金属中得出的。最近，人们越来越兴趣对环境友好，更便宜的碱性和碱金属氢化物催化剂，通常被发现为二聚体甚至更高的低聚物。据报道，在轻度条件下，据报道了显着的主要基团催化剂，用于激活的共轭烷烃的氢化，甚至是未活化的1-烯烃以及醛（phhc = nr，r = tbu，ipr，pH）。然而，详细的催化机制，尤其是潜在的（金属）合作社和（配体）空间效应以理解此类催化系统的效果往往尚不清楚。最近，与道格拉斯·史蒂芬（Douglas W.和C-H键。由于需要大金属氢化物催化剂的复杂电子结构，因此需要与不饱和底物和溶剂分子以及对反应路径的潜在广泛探索的其他相互作用，因此对这种催化氢反应的详细机械研究是计算上挑战的。在该项目中，基于有效的GFN2-XTB方法（构象和反应路径探索），分散校正的低成本DFT（快速结构筛选）以及高级分散校正的DFT方法（准确的结构和能量的准确dlpno-cccsd（必要）在必要时采用高度相关的dlpno-ccsd（t），在各种方法中，一个反应效果，一个反应的效果，效果效果，效果效率，并效果效率。路径，以详细识别催化机制。通过与实验的紧密相互作用，该项目的目的是对主要基团金属催化剂催化的氢化反应以及环境友好和廉价的新代氢化催化剂的理性设计。