83330-75-0Relevant academic research and scientific papers
Zn(ii)@TFP-DAQ COF: An efficient mesoporous catalyst for the synthesis of: N -methylated amine and carbamate through chemical fixation of CO2
Sarkar, Priyanka,Chowdhury, Arpita Hazra,Riyajuddin, Sk.,Biswas, Surajit,Ghosh, Kaushik,Islam, Sk. Manirul
, p. 744 - 752 (2020/01/31)
Selective N-methylation and carbamate formation reactions were demonstrated via the chemical incorporation of CO2 using a Zn-loaded TFP-DAQ COF (covalent organic framework) as an active catalyst under mild reaction conditions. The selective N-methylation and N-formylation reactions were performed by simply varying the type of solvent. The Zn(ii)@TFP-DAQ COF catalyst was characterized via different characterization techniques such as PXRD, FTIR, UV-vis, N2 adsorption-desorption studies, FESEM and TEM. The catalyst material showed pores in the mesoporous region with a high surface area of 1117.375 m2 g-1. The as-synthesized material was applied as a cheap catalyst for the N-methylation of secondary amines and in carbamate formation reactions with high yields of the desired products up to 98.5% and 97%, respectively, with >99% selectivity. The catalyst was found to be completely heterogeneous and reusable for multiple reaction cycles.
Modified Graphene Oxide Based Zinc Composite: an Efficient Catalyst for N-formylation and Carbamate Formation Reactions Through CO2 Fixation
Khatun, Resmin,Biswas, Surajit,Islam, Sarikul,Biswas, Imdadul Haque,Riyajuddin, Sk,Ghosh, Kaushik,Islam, Sk Manirul
supporting information, p. 1303 - 1312 (2019/01/25)
Catalytic fixation of CO2 through chemical reactions is always a challenging task of synthetic chemistry. This paper represents the design and synthesis of an eco-friendly low cost zinc metal containing heterogeneous catalyst of aminically modified Graphene Oxide. Characterization of the catalyst has been carried out by Raman and FTIR spectra, AAS, XRD, TEM, SEM, EDX and N2 adsorption desorption studies. It was found that the catalyst was very proficient for the CO2 fixation through N-formylation and carbamate formation reactions of amines. Catalytic N-formylation reaction of both aromatic and aliphatic amines gave high yield of corresponding formylated products in presence of polymethylhydrosiloxane (PMHS) as reducing agent under 1 bar CO2 pressure and mild temperature. Formation of carbamates from aniline or its derivatives and alkyl/aryl bromide with good product selectivity was also achieved under same CO2 pressure in presence of our synthesized catalyst at room temperature with solvent-free condition. The catalyst is reusable and e?cient even after six cycles.
Cu-Mediated C-H 18F-Fluorination of Electron-Rich (Hetero)arenes
McCammant, Matthew S.,Thompson, Stephen,Brooks, Allen F.,Krska, Shane W.,Scott, Peter J. H.,Sanford, Melanie S.
supporting information, p. 3939 - 3942 (2017/07/26)
This communication describes a method for the nucleophilic radiofluorination of electron-rich arenes. The reaction involves the initial C(sp2)-H functionalization of an electron-rich arene with MesI(OH)OTs to form a (mesityl)(aryl)iodonium salt
Carbamoylimidazolium and thiocarbamoylimidazolium salts: Novel reagents for the synthesis of ureas, thioureas, carbamates, thiocarbamates and amides
Grzyb, Justyna A.,Shen, Ming,Yoshina-Ishii, Chiaki,Chi,Brown, R. Stanley,Batey, Robert A.
, p. 7153 - 7175 (2007/10/03)
Carbamoylimidazolium salts act as efficient N,N-disubstituted carbamoylating reagents. These salts are readily prepared by the sequential treatment of secondary amines with N,N′-carbonyldiimidazole (CDI) and iodomethane. The carbamoylimidazolium salts are more efficient carbamoyl transfer reagents than the intermediate carbamoylimidazoles, as a result of the 'imidazolium' effect. Kinetic studies on the base promoted hydrolysis of both carbamoylimidazoles and carbamoylimidazolium salts reveal over a hundred-fold rate acceleration. The salts react with amines, thiols, phenols/alcohols, and carboxylic acids in high yields, without the need for subsequent chromatographic purification of the products, producing ureas, thiocarbamates, carbamates, and amides, respectively. Analogous thiocarbamoylimidazolium salts were also synthesized from secondary amines and N,N′-thiocarbonyldiimidazole (TCDI), followed by methylation with iodomethane.
Deallyloxy- and debenzyloxycarbonylation of protected alcohols, amines and thiols via a naphthalene-catalysed lithiation reaction
Behloul, Cherif,Guijarro, David,Yus, Miguel
, p. 9319 - 9324 (2007/10/03)
The naphthalene-catalysed lithiation of Alloc- and Cbz-protected alcohols, amines and thiols in THF at 0°C led, after quenching with methanol, to the recovery of the free alcohols, amines and thiols in short reaction times and with very good yields. The selectivity for the removal of the Alloc- or the Cbz- group in a polyfunctionalised substrate has been studied. The selective reductive cleavage of a benzylic carbon-oxygen bond was achieved in the presence of an allylic carbon-oxygen or carbon-nitrogen bond. This method represents a great improvement in comparison with the previously reported deprotection procedures by dissolving metals, since it avoids the use of the toxic liquid ammonia and, therefore, the need to perform the reaction at low temperatures.
Mild and selective deprotection of carbamates with Bu4NF
Jacquemard, Ulrich,Bénéteau, Valérie,Lefoix, Myriam,Routier, Sylvain,Mérour, Jean-Yves,Coudert, Gérard
, p. 10039 - 10047 (2007/10/03)
A new mild method allowing the removal of carbamates using TBAF in THF is reported. Reactions were performed on indole, indoline, N-methyl aniline, aniline and tryptamine derivatives. The observed selectivity according to the carbamates or the substrates is discussed. A mechanism is postulated. Graphical Abstract
A new protocol for the formation of carbamates and thiocarbamates using carbamoyl imidazolium salts
Batey, Robert A.,Yoshina-Ishii, Chiaki,Taylor, Scott D.,Santhakumar
, p. 2669 - 2672 (2007/10/03)
Carbamoyl imidazolium salts are demonstrated to act as useful carbamoylation reagents, in reactions with alcohols, phenols, thiols and thiophenols to form carbamates and thiocarbamates under relatively mild conditions. The salts are stable and easily prepared from the corresponding amines using CDI.
Chemoselective alkoxycarbonylation reagent having trifluoromethylsulfonyl-4-trifluoromethylanilide as a leaving group
Yasuhara, Tomohisa,Nagaoka, Yasuo,Tomioka, Kiyoshi
, p. 2233 - 2234 (2007/10/03)
N-Benzyloxy- and N-tert-butoxycarbonyltrifluoromethylsulfonyl-4-trifluoromethylanilides were prepared and were found to be chemoselective and shelf-storable alkoxycarbonylation reagents.
