Nonsolvent Application of Ionic Liquids: Organo-Catalysis by 1-Alkyl-3-methylimidazolium Cation Based Room-Temperature Ionic Liquids for Chemoselective N-tert-Butyloxycarbonylation of Amines and the Influence of the C-2 Hydrogen on Catalytic Efficiency was written by Sarkar, Anirban;Roy, Sudipta Raha;Parikh, Naisargee;Chakraborti, Asit K.. And the article was included in Journal of Organic Chemistry in 2011.Application of 18437-66-6 This article mentions the following:
Imidazolium ionic liquids such as [bmim]+·Tf2N– (I; bmim = 1-butyl-3-methylimidazolium) efficiently catalyze the chemoselective N-tert-butyloxycarbonylation of amines; the catalyst can be recycled by extraction of the product into ether followed by heating under vacuum. The ionic liquid catalyst activates di-tert-Bu dicarbonate electrophilically through formation of a bifurcated hydrogen bond with the C-2 hydrogen of the imidazolium cation; the role of the C2 proton in catalysis is supported by the change in the 1H NMR shift of the imidazolium C-2 hydrogen of I from δ 8.39 to δ 8.66 in the presence of Boc2O and by the significantly reduced activities of analogous 1-butyl-2,3-dimethylimidazolium ionic liquids lacking C-2 hydrogens. Alkylamines are tert-butoxycarbonylated more rapidly than aromatic amines, allowing the chemoselective protection of the benzylamine moiety of 4-aminobenzylamine; Boc protection of piperidine and 1-piperidineethanamine in the presence of I yields a 62:38 mixture of the Boc piperidine and tert-Bu piperidineethylcarbamate. The efficiencies of the Boc protection of 3-chloro-4-fluoroaniline in the presence of I and in the presence of Lewis acids (from literature references) are compared. In the experiment, the researchers used many compounds, for example, tert-Butyl (4-chlorophenyl)carbamate (cas: 18437-66-6Application of 18437-66-6).
tert-Butyl (4-chlorophenyl)carbamate (cas: 18437-66-6) belongs to organic chlorides. Organic chlorides are compounds containing a carbon-chlorine bond, which are widely used in the oil field as a wax dissolver. Alkanes and aryl alkanes may be chlorinated under free radical conditions, with UV light. However, the extent of chlorination is difficult to control.Application of 18437-66-6
Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics