A SOLVENT-FREE AND FORMALIN-FREE ESCHWEILER-CLARKE METHYLATION FOR AMINES
摘要:
Primary and secondary amines are N-methylated by a mixture of paraformaldehyde and oxalic acid dihydrate in good to excellent yields. The reaction proceeds without involvement of organic solvents and toxic formalin. Reaction temperatures of 100degreesC are required for the decomposition of oxalic acid into the intermediate formic acid which acts as the actual reductant. The reaction conditions have been optimized, and the mechanism has been elucidated by means of deuteration experiments.
Efficient Cobalt-Catalyzed Methylation of Amines Using Methanol
作者:Zhenghui Liu、Zhenzhen Yang、Xiaoxiao Yu、Hongye Zhang、Bo Yu、Yanfei Zhao、Zhimin Liu
DOI:10.1002/adsc.201701044
日期:2017.12.19
The methylation of amines using methanol is a promising route to synthesize N‐methylamines, and the development of cheap and efficient catalytic system for this reaction is of great significance. Herein, we reported a cobalt (Co)‐based catalytic system, which was in situ formed from commercially available Co precursor and a tetradentate phosphine ligand P(CH2CH2PPh2)3 combined with K3PO4. This catalystic
使用甲醇对胺进行甲基化是合成N-甲胺的有前途的途径,为此反应开发廉价,高效的催化体系具有重要意义。在本文中,我们报道了一种基于钴(Co)的催化体系,该体系由可商购获得的Co前驱体和四齿膦配体P(CH 2 CH 2 PPh 2)3与K 3 PO 4结合而成。该催化体系对于从脂肪族胺选择性生产二甲基化产物和从芳香族胺选择性生成单甲基化产物非常有效。通过控制和同位素标记实验进一步研究了反应机理。