Coordination with RuCl2(PPh3)dppb gave ruthenium(II) N-heterocyclic complexes 4b–d. The structure of complex 4b was fully illuminated by X-ray crystallography. The steric environment of these chiral ruthenium complexes 4b–d was evaluated in asymmetric transfer hydrogenation (ATH) of prochiral ketones in the presence of NaOiPr by using 2-propanol as the hydrogen source and solvent. The resultant catalytic
从光学纯的氨基酸开始合成了一组新的基于喹唑啉的手性配体。与RuCl 2(PPh 3)dppb配位得到钌(II)N-杂环配合物4b–d。配合物4b的结构通过X射线晶体学被完全照亮。通过使用2-丙醇作为氢源和溶剂,在NaO i Pr存在的情况下,在手性酮的不对称转移氢化(ATH)中评估了这些手性钌配合物4b-d的空间环境。所得的催化体系可以实现非常好的对映选择性(高达91%)和高产率(高达99%)。
Synthesis, structure and catalytic properties of CNN pincer palladium(ii) and ruthenium(ii) complexes with N-substituted-2-aminomethyl-6-phenylpyridines
作者:Tao Wang、Xin-Qi Hao、Xiao-Xue Zhang、Jun-Fang Gong、Mao-Ping Song
DOI:10.1039/c1dt10331h
日期:——
6-bromo-2-picolinaldehyde in two steps. Reaction of 2a–c with PdCl2 in toluene in the presence of triethylamine gave the CNN pincer Pd(II) complexes 3a–c in 18-28% yields. The CNN pincer Ru(II) complex 5 containing a Ru-NHR functionality could be obtained in a 71% yield by treatment of 2c with a Ru(II) precursor instead of PdCl2. Additionally, the related CNN pincer Ru(II) complex 7 containing a Ru–NH2 functionality
reacts with Na[BArf4] and PCy3, affording the cationic trans-[Ru(CNNOMe)(CO)(PCy3)(PPh3)][BArf4] (5) (92% yield). These robust pincer complexes display remarkably high catalytic activity in the transfer hydrogenation (TH) of lignocellulosic biomass carbonylcompounds, using 2-propanol at reflux in a basic medium (NaOiPr or K2CO3). Thus, furfural, 5-(hydroxymethyl)furfural and Cyrene are reduced to the
The new chiral aminomethyl quinazoline (amq) type ligand derivedfroml-phenylalanine was synthesized and coordinated with [RuCl2(PPh3)dppb] to obtain ruthenium(II) complex. This catalyst displayed considerable reactivity (up to 97% ee and 99% conversion) in the asymmetric transfer hydrogenation of ketones using 2-propanol as a hydrogen source in the presence of NaOiPr.
合成了一种新的由1-苯基丙氨酸衍生的手性氨基甲基喹唑啉(amq)型配体,并与[RuCl 2(PPh 3)dppb]配位得到钌(II)配合物。在NaO i Pr存在的情况下,使用2-丙醇作为氢源,在酮的不对称转移加氢中,该催化剂表现出可观的反应性(高达97%ee和99%的转化率)。
Complexes of Ruthenium with 2-(Aminomethyl)Pyridines and Phosphines, their Preparation and Use as Catalysts
申请人:Baratta Walter
公开号:US20080249308A1
公开(公告)日:2008-10-09
The invention relates to a new class of ruthenium (II) complexes containing as ligands 2-(aminomethyl)pyridines and phosphines, proven to be extremely active catalysts in the reduction of ketones to alcohols via hydrogen transfer. By using 2-propanol as the hydrogen source with the ruthenium complexes, high yields of the corresponding alcohol can be rapidly obtained starting from linear and cyclic alkyl aryl, dialkyl and diaryl ketones. The conversion of ketones to alcohols can reach 100% if operating in a gaseous hydrogen atmosphere (2-3 atm). Where the phosphines used are optically active, starting from prochiral ketone compounds various types of optically active alcohols can be produced, being important intermediates in the pharmaceutical industry, in the agrochemical industry and for fine chemicals generally.