83871-57-2Relevant academic research and scientific papers
Phosphine ligands stabilized Cu(I) catalysts for carbene insertion into the N-H bond
Ramakrishna, Kankanala,Sivasankar, Chinnappan
, p. 122 - 129 (2016/02/03)
Phosphine ligands have been successfully used along with Cu(I) for several catalytic reactions, nevertheless these ligands were less explored relatively for carbene involved reactions owing to the formation of carbene-phosphine ylides. In this report we successfully used three different phosphine stabilized Cu(I) complexes (1-3) as catalysts for chemoselective carbene insertion into the N-H bond of different aromatic amines over the formation of olefin (carbene dimerized product). In order to understand the substrate scope, different α-diazo esters have been reacted with large number of amines and all the reactions produced reasonably good yields under normal experimental conditions (38 examples). All the carbene inserted products have been isolated by column chromatography and fully characterized using standard spectroscopic techniques without any ambiguities. Several control reactions have been conducted in order to understand the importance of the type of phosphine ligands used in the catalysts 1-3 and found that without these catalysts we observed less selectivity (more of olefin as the product over N-H inserted product) and low yield. From this present study, it can be noted that the rigid framework phosphine ligands would be the better choice for carbene chemistry. The results obtained from the current studies would inspire chemists to develop more novel Cu(I)-phosphine catalysts for carbene related reactions including asymmetric versions in the near future.
Electrosynthesis of N-Substituted DL-Arylglycineesters and 1,2-Diarylamino-1,2-diarylethanes by Cathodic Reduction of Azomethines in the Presence of Carbon Dioxide
Hess, U.,Thiele, R.
, p. 385 - 399 (2007/10/02)
The electroreduction of the N-arylidene-arylamines 1-12 in CO2-saturated solvents of low proton availability as DMF at markedly more positive potentials than carbon dioxide end up in carboxylating the C-atom and hydrogenating the nitrogen of the C=N-double bond.The resulting N-arylsubstituted DL-arylglycines and traces of carbamates may be isolated as esters, adding ethylchloride during the electrolysis.A competing pathway of the electrocarboxylation is the C-C-hydrodimerisation and the hydrogenation of the C=N-double bond, whose importance increases with the water content of the solvent.Based on cyclic-voltametric evidence and product analysis the mechanism of the reductive electrocarboxylation reaction is discussed in terms of nucleophilic attack of the azomethine anion radical on a proton or CO2.
