1541-19-1Relevant articles and documents
Understanding Ni(II)-Mediated C(sp3)-H Activation: Tertiary Ureas as Model Substrates
Beattie, D. Dawson,Grunwald, Anna C.,Perse, Thibaut,Schafer, Laurel L.,Love, Jennifer A.
, p. 12602 - 12610 (2018)
We report a mechanistic study of C(sp3)-H bond activation mediated by nickel. Cyclometalated Ni(II) ureate [(PEt3)Ni(?3-C,N,N-(CH2)N(Cy)(CO)N((N)-quinolin-8-yl))] was synthesized and isolated from the urea precu
The reactions of organoboranes with N-chloro-N-sodiocarbamates: A novel synthesis of N-alkylcarbamates
Wachter-Jurcsak,Scully Jr.
, p. 5261 - 5264 (1990)
Trialkylboranes react with N-chloro-N-sodiocarbamates to form N-alkylcarbamates in yields ranging from 50-88%. The reaction is best carried out without intermediate isolation of the N-chlorocarbamate salt. Only one of the alkyl groups of the trialkylborane is utilized.
Halogen-free process for the conversion of carbon dioxide to urethanes by homogeneous catalysis
Abla,Choi,Sakakura
, p. 2238 - 2239 (2001)
Carbon dioxide is converted to urethanes (carbamic acid derivatives) through reaction with amine and alcohol catalyzed by tin complexes; the addition of acetals as a dehydrating agent under high CO2 pressure is the key to achieve high yields.
A simple method for the synthesis of carbamates
Angeles,Santillan,Martinez,Ramirez,Moreno,Salmon,Martinez
, p. 2441 - 2447 (1994)
A new method for carbamate synthesis using aryl and alkylamines with sodium hydride and diethylcarbonate in dry benzene is described.
Activation of carbon dioxide by bicyclic amidines
Perez, Eduardo R.,Santos, Regina H. A.,Gambardella, Maria T. P.,De Macedo, Luiz G. M.,Rodrigues-Filho, Ubirajara P.,Launay, Jean-Claude,Franco, Douglas W.
, p. 8005 - 8011 (2004)
Activation of the carbon dioxide molecule was achieved using bicyclic amidines (DBU, PMDBD, and DBN). The solution reaction of CO2 with amidines yielded the corresponding zwitterionic complexes through the formation of a N-CO2 bond. 13C NMR data confirmed the carbamic nature of the carbamic zwitterions, DBU-CO2 and PMDBD-CO2. However, when these adducts were crystallized, the X-ray analyses of the single crystals were in agreement with bisamidinium bicarbonate salt structures, indicating that structural changes occurred in the crystallization process. The elemental and thermogravimetric analysis data for the carbamic zwitterions, DBU-CO2 and PMDBD-CO2, initially obtained by the direct reaction of amidines with CO2, suggest that these molecules are probably associated with one molecule of water by hydrogen-bond formation (amidinium+-COO-...H2O). A correlation was observed between the thermal stability and the transcarboxylating activity for the amidine-CO2 complexes. Theoretical calculations of hardness were performed at the B3LYP/cc-pVTZ level of theory and showed concordance with the experimental reactivity of DBU and PMDBD toward CO2.
Urethanes synthesis from oxamic acids under electrochemical conditions
Ogbu, Ikechukwu Martin,Lusseau, Jonathan,Kurtay, Gülbin,Robert, Frédéric,Landais, Yannick
, p. 12226 - 12229 (2020/10/26)
Urethane synthesis via oxidative decarboxylation of oxamic acids under mild electrochemical conditions is reported. This simple phosgene-free route to urethanes involves an in situ generation of isocyanates by anodic oxidation of oxamic acids in an alcoholic medium. The reaction is applicable to a wide range of oxamic acids, including chiral ones, and alcohols furnishing the desired urethanes in a one-pot process without the use of a chemical oxidant.
Chemoselective synthesis of carbamates using CO2 as carbon source
Riemer, Daniel,Hirapara, Pradipbhai,Das, Shoubhik
, p. 1916 - 1920 (2018/08/17)
Synthesis of carbamates directly from amines using CO2 as the carbon source is a straightforward and sustainable approach. Herein, we describe a highly effective and chemoselective methodology for the synthesis of carbamates at room temperature and atmosp
N-Substituted carbamate synthesis using urea as carbonyl source over TiO2-Cr2O3/SiO2 catalyst
Wang, Peixue,Ma, Yubo,Liu, Shimin,Zhou, Feng,Yang, Benqun,Deng, Youquan
, p. 3964 - 3971 (2015/07/15)
The use of urea as an active form of carbon dioxide is a feasible way to substitute phosgene in the chemical industry. This paper reports an effective route for the synthesis of N-substituted carbamates from amines, urea and alcohols. Under the optimized reaction conditions, several important N-substituted carbamates were successfully synthesized in 95-98% yields over a TiO2-Cr2O3/SiO2 catalyst. The catalyst could be reused for several runs without deactivation. The catalysts were characterized by BET, XPS, XRD, and TPD, which suggested that the strength and amount of the acidic and basic sites might be the major reason for the high catalytic activity of TiO2-Cr2O3/SiO2.
Direct reductive amination using triethylsilane and catalytic bismuth(III) chloride
Matsumura, Takehiko,Nakada, Masahisa
, p. 1829 - 1834 (2014/03/21)
Direct reductive amination (DRA) using triethylsilane (TESH) and catalytic bismuth(III) chloride (BiCl3) is described for the first time. The use of TESH and BiCl3 provides easy handling, low cost, non-toxicity, and a mild Lewis acid activity, thereby meeting the demand for green and sustainable chemistry. The developed DRA is highly chemoselective and applicable to less-basic amines. The experimental results of this study revealed that the developed DRA could be catalyzed by BiCl3, which was gradually reduced to Bi(0) or bismuth with a low valency by TESH, but TESCl, Bi(0), and Bi(0) with TESCl catalyzed the DRA to some extent.
Stereoselective direct reductive amination of ketones with electron-deficient amines using Re2O7/NaPF6 catalyst
Das, Braja Gopal,Ghorai, Prasanta
supporting information, p. 4379 - 4382 (2013/08/23)
The first example of direct reductive amination (DRA) of ketones with electron-deficient amines (EDA) such as Cbz-, Boc-, EtOCO-, Fmoc-, Bz-, ArSO2-, etc. protected amines have been achieved using catalytic Re2O7/NaPF6. Excellent chemoselectivities as well as diastereoselectivity (for 2-alkyl cyclohexanones) were obtained. The Royal Society of Chemistry 2013.
