from a rhodium center to imine substrates in a biomimetic way. Under both transfer hydrogenation and reductiveamination reaction conditions, the catalyst exhibited good selectivity towards CN bonds. With the catalyst, 34 imines were transfer hydrogenated to corresponding amines and a key intermediate of retigabine was prepared via reductiveamination in a greener way. According to the NMR observations
将基于金属和键合辅因子模拟物之间合作的策略应用于 CN 键的转移氢化。我们设计并合成了一种含有 1,3-二甲基苯并咪唑部分的铑配合物,它可以以仿生的方式将氢化物从铑中心转移到亚胺底物上。在转移氢化和还原胺化反应条件下,催化剂对C N 键表现出良好的选择性。使用该催化剂,34个亚胺被转移氢化成相应的胺,并通过还原胺化以更绿色的方式制备了瑞替加滨的关键中间体。根据核磁共振观察和同位素实验,提出了这种仿生还原碳氮键的合理机制。
Amine Synthesis through Mild Catalytic Hydrosilylation of Imines using Polymethylhydroxysiloxane and [RuCl2(arene)]2 Catalysts
作者:Bin Li、Jean-Baptiste Sortais、Christophe Darcel、Pierre H. Dixneuf
DOI:10.1002/cssc.201100585
日期:2012.2.13
Tolerate silicone! The stable [RuCl2(p‐cymene]2 complex is an efficient catalyst for the direct chemoselective hydrosilylation of functionalized aldimines and ketimines into amines, usingpolymethylhydroxysiloxane as an inexpensive, stable, and safe hydrosilane source. The catalysis operates in ethanol, under air at room temperature, and tolerates the ketone ester and alkene functionality.
A Highly Efficient Base-Metal Catalyst: Chemoselective Reduction of Imines to Amines Using An Abnormal-NHC–Fe(0) Complex
作者:Mrinal Bhunia、Pradip Kumar Hota、Gonela Vijaykumar、Debashis Adhikari、Swadhin K. Mandal
DOI:10.1021/acs.organomet.6b00478
日期:2016.9.12
A base-metal, Fe(0)-catalyzed hydrosilylation of imines to obtain amines is reported here which outperforms its noble-metal congeners with the highest TON of 17000. The catalyst, (aNHC)Fe(CO)(4), works under very mild conditions, with extremely low catalyst loading (down to 0.005 mol %), and exhibits excellent chemoselectivity. The facile nature of the imine reduction under mild conditions has been further demonstrated by reducing imines towards expensive commercial amines and biologically important N-alkylated sugars, which are difficult to achieve otherwise. A mechanistic pathway and the source of chemoselectivity for imine hydrosilylation have been proposed on the basis of the well-defined catalyst and isolable intermediates along the catalytic cycle.