atom‐economic direct amidation of alcohols with amines has been recently highlighted as an attractive and promising transformation. Among the versatile reported catalytic systems, in situ generated N‐heterocycliccarbene (NHC)/ruthenium (Ru) catalytic systems have demonstrated their advantages such as easy operation and use of commercial Ru compounds. However, the existing catalyst loadings are relatively
Ruthenium-Based Catalytic Systems Incorporating a Labile Cyclooctadiene Ligand with N-Heterocyclic Carbene Precursors for the Atom-Economic Alcohol Amidation Using Amines
作者:Cheng Chen、Yang Miao、Kimmy De Winter、Hua-Jing Wang、Patrick Demeyere、Ye Yuan、Francis Verpoort
DOI:10.3390/molecules23102413
日期:——
Herein, we identified a highly active in situ N-heterocyclic carbene (NHC)/ruthenium (Ru) catalyticsystem for this amide synthesis. Various substrates, including sterically hindered ones, could be directly transformed into the corresponding amides with the catalyst loading as low as 0.25 mol.%. In this system, we replaced the p-cymene ligand of the Ru source with a relatively labile cyclooctadiene
In situ Generated Ruthenium Catalyst Systems Bearing Diverse N-Heterocyclic Carbene Precursors for Atom-Economic Amide Synthesis from Alcohols and Amines
The transition‐metal‐catalyzed direct synthesis of amides fromalcohols and amines is herein demonstrated as a highly environmentally benign and atom‐economic process. Among various catalyst systems, in situ generated N‐heterocyclic carbene (NHC)‐based ruthenium (Ru) halide catalyst systems have been proven to be active for this transformation. However, these existing catalyst systems usually require
本文证明了由醇和胺进行的过渡金属催化酰胺的直接合成是一种对环境有益且原子经济的过程。在各种催化剂体系中,已证明原位生成的基于N-杂环卡宾(NHC)的卤化钌(Ru)催化剂体系对于这种转化是有效的。然而,这些现有的催化剂体系通常需要额外的配体以获得令人满意的结果。在这项工作中,通过广泛筛选各种NHC前体,我们发现了一种有效的酰胺合成活性原位催化剂体系,而无需任何其他配体。值得注意的是,发现该催化剂体系对基质和各种电子不足的基质的电子效应不敏感,与我们以前的催化剂体系不具有高反应活性的化合物,可以用来有效地提供相应的酰胺。此外,进行了机械研究以为优化的催化剂体系的高活性提供理论依据。NMR规模反应表明,氢化钌中间体迅速形成(添加醇底物后,在1 H NMR光谱中的δ = -7.8 ppm对于建立高催化剂活性至关重要。此外,HRMS分析提供了原位生成的催化剂体系的可能结构。
Well‐defined N‐heterocyclic carbene/ruthenium complexes for the alcohol amidation with amines: The dual role of cesium carbonate and improved activities applying an added ligand
Dehydrogenative amide bond formationfrom alcohols and amines has been regarded as an atom‐economic and sustainable process. Among various catalytic systems, N‐heterocycliccarbene (NHC)‐based Ru catalytic systems have attracted growing interest due to the outstanding properties of NHCs as ligands. Herein, an NHC/Ru complex (1) was prepared and its structure was further confirmed with X‐ray crystallography
由醇和胺形成的脱氢酰胺键被认为是原子经济且可持续的过程。在各种催化体系中,基于N杂环卡宾(NHC)的Ru催化体系由于其作为配体的NHC的出色性能吸引了越来越多的关注。本文制备了NHC / Ru络合物(1),并通过X射线晶体学进一步证实了其结构。在Cs 2 CO 3的存在下,两个基于NHC / Ru的催化体系据报道对这种酰胺合成具有活性。不包含任何添加的配体的系统A要求催化剂负载为1.00mol%。有趣的是,通过添加NHC前体(L)。L的量和其他条件的优化产生了体系B,该体系是更有效的体系,其Ru负载量低至0.25mol%。此外,从1和Cs 2 CO 3的回流甲苯中鉴定出NHC-Ru-碳酸盐络合物6,进一步研究表明6是该催化反应的重要中间体。基于以上结果,我们声称Cs 2 CO 3的作用是促进关键中间体6的形成。另一方面,它为选择性酰胺的形成提供了优化的碱性。
Process for producing benzylamine derivative
申请人:Ito Akinori
公开号:US20060155141A1
公开(公告)日:2006-07-13
Disclosed is a process for producing a benzylamine derivative represented by the general formula (3):
wherein X
1
, R
1
and R
2
are as defined below, which comprises reacting a benzyl derivative represented by the general formula (1):
wherein X
1
represents a halogen atom and R
1
represents an acyl group, with a haloacyl compound represented by the general formula (2):
R
2
—X
2
(2)
wherein X
2
represents a halogen atom and R
2
represents an acyl group, in the presence of Lewis acid. According to this method, a benzylamine derivative as an intermediate, which is useful for the preparation of a carbamate-based agricultural or horticultural bactericide, can be preferably prepared.