Mechanistic Investigation of Bis(imino)pyridine Manganese Catalyzed Carbonyl and Carboxylate Hydrosilylation
作者:Tufan K. Mukhopadhyay、Christopher L. Rock、Mannkyu Hong、Daniel C. Ashley、Thomas L. Groy、Mu-Hyun Baik、Ryan J. Trovitch
DOI:10.1021/jacs.7b00879
日期:2017.4.5
recently reported a bis(imino)pyridine (or pyridine diimine, PDI) manganese precatalyst, (Ph2PPrPDI)Mn (1), that is active for the hydrosilylation of ketones and dihydrosilylation of esters. In this contribution, we reveal an expanded scope for 1-mediated hydrosilylation and propose two different mechanisms through which catalysis is achieved. Aldehyde hydrosilylation turnover frequencies (TOFs) of
我们最近报道了一种双(亚氨基)吡啶(或吡啶二亚胺,PDI)锰预催化剂,(Ph2PPrPDI)Mn (1),它对酮的氢化硅烷化和酯的二氢硅烷化具有活性。在这项贡献中,我们揭示了 1 介导的氢化硅烷化的扩展范围,并提出了两种不同的催化机制。已经实现了高达 4900 min-1 的醛氢化硅烷化转换频率 (TOF),这是第一行金属催化羰基氢化硅烷化报告的最高值。此外,1 已显示介导甲酸二氢硅烷化,前导 TOF 可达 330 min-1。在化学计量和催化条件下,发现将 PhSiH3 添加到 (Ph2PPrPDI)Mn 中会导致部分转化为新的抗磁性氢化物。通过将 NaEt3BH 添加到 (Ph2PPrPDI)MnCl2 中,实现了 (Ph2PPrPDI)MnH (2) 的独立制备,单晶 X 射线衍射分析表明该复合物具有封闭的三角双锥体固态几何形状。当 2,2,2-三氟苯乙酮加入到 1 中时,自由基转移产生