5602-96-0Relevant articles and documents
Reductive Carbonylation of Nitroarenes Using a Heterogenized Phen-Pd Catalyst
Padmanaban, Sudakar,Ganesan, Vinothkumar,Yoon, Sungho,Lee, Yunho
, p. 1552 - 1561 (2022/01/27)
The reductive carbonylation of nitroarenes in the presence of MeOH and CO(g) is one of the interesting alternative routes without utilizing toxic phosgene and corrosive HCl generation for the synthesis of industrially useful carbamate compounds that serve as important intermediates for polyurethane production. Since homogeneous palladium catalysts supported by phen (phen = 1,10-phenanthroline) are known to be effective for this catalysis, the heterogenized Pd catalyst was developed using the phen-containing solid support. In this study, we report the synthesis of a phen-based heterogeneous Pd catalyst, Pd@phen-POP, which involves the solvent knitting of a phen scaffold via the Lewis-acid-catalyzed Friedel-Crafts reaction using dichloromethane as a source for linker in the presence of AlCl3 as a catalyst. The resulting solid material has been thoroughly characterized by various physical methods revealing high porosity and surface area. Similar to the homogeneous pallidum catalyst, this heterogeneous catalyst shows efficient reductive carbonylation of various nitroarenes. The catalytic reaction using nitrobenzene as a model compound presents a high turnover number (TON = 530) and a reasonable turnover frequency (TOF = 45 h-1), with a high selectivity (92%) for the carbamate formation. According to the recycling study, the heterogeneous catalyst is recyclable and retains ～90% of the original reactivity in each cycle.
METHOD FOR PRODUCING CARBAMATE
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Paragraph 0014-0024, (2021/08/13)
PROBLEM TO BE SOLVED: To provide a method that can produce carbamate with high yield and high selectivity, and excellent economical efficiency, using more different kinds of amines. SOLUTION: A method for producing carbamate has a reaction step where, in the presence of calcium carbide and potassium carbonate, a reaction is induced among amine, methanol, and carbon dioxide. The reaction step is preferably performed at a temperature of 165-180°C. The reaction step is preferably performed at a carbon dioxide pressure of 3-5 MPa. The reaction step is preferably performed using an acetonitrile solvent. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2021,JPOandINPIT
Copper-Catalyzed Coupling of Amines with Carbazates: An Approach to Carbamates
Wang, Song-Ning,Zhang, Guo-Yu,Shoberu, Adedamola,Zou, Jian-Ping
, p. 9067 - 9075 (2021/07/19)
A new approach for the preparation of carbamatesviathe copper-catalyzed cross-coupling reaction of amines with alkoxycarbonyl radicals generated from carbazates is described. This environmentally friendly protocol takes place under mild conditions and is compatible with a wide range of amines, including aromatic/aliphatic and primary/secondary substrates.
Atomically Dispersed Copper on N-Doped Carbon Nanosheets for Electrocatalytic Synthesis of Carbamates from CO2 as a C1 Source
Li, Shi-Ming,Shi, Yi,Zhang, Jing-Jie,Wang, Ying,Wang, Huan,Lu, Jia-Xing
, p. 2050 - 2055 (2021/03/24)
The synthesis of carbamates by electrocatalytic reduction of CO2 is an effective method to realize the utilization of CO2 resources. The development of high-performance electrocatalysts to complete this process more efficiently is of great significance to sustainable development. Owing to their unique structural characteristics, single-atom catalysts are expected to promote the reaction process more efficiently. In this study, an atomically dispersed Cu species on N-doped carbon nanosheet composite material (Cu?N?C) was prepared by metal-organic framework derivatization. Compared with traditional Cu bulk electrodes, the Cu?N?C material has better catalytic performance for the synthesis of methyl N-phenylcarbamate; and the optimized yield reached 71 % at room temperature and normal pressure. The Cu?N?C material has good stability that the catalytic performance does not decrease after repeated use for 10 times. In addition, the Cu?N?C material has good applicability to this catalytic system, and a variety of amines can be smoothly converted into corresponding carbamates.
N-Aryl and N-Alkyl Carbamates from 1 Atmosphere of CO2
Chen, Ming-Yu,Choe, Yoong-Kee,Choi, Jun-Chul,Fukaya, Norihisa,Hamura, Satoshi,Koizumi, Hiroki,Matsumoto, Kazuhiro,Matsumoto, Seiji,Shigeyasu, Shinji,Takeuchi, Katsuhiko,Yuan, Hao-Yu
supporting information, p. 18066 - 18073 (2021/12/08)
We have successfully isolated and characterized the zinc carbamate complex (phen)Zn(OAc)(OC(=O)NHPh) (1; phen=1,10-phenanthroline), formed as an intermediate during the Zn(OAc)2/phen-catalyzed synthesis of organic carbamates from CO2, amines, and the reusable reactant Si(OMe)4. Density functional theory calculations revealed that the direct reaction of 1 with Si(OMe)4 proceeds via a five-coordinate silicon intermediate, forming organic carbamates. Based on these results, the catalytic system was improved by using Si(OMe)4 as the reaction solvent and additives like KOMe and KF, which promote the formation of the five-coordinated silicon species. This sustainable and effective method can be used to synthesize various N-aryl and N-alkyl carbamates, including industrially important polyurethane raw materials, starting from CO2 under atmospheric pressure.
Methoxycarbonylation of Alkyl-, Cycloalkyl-, and Arylamines with Dimethyl Carbonate in the Presence of Binder-Free Zeolite
Khazipova, A. N.,Khusnutdinov, R. I.,Mayakova, Yu. Yu.,Shchadneva, N. A.
, p. 1228 - 1235 (2020/10/02)
Abstract: Methyl N-alkyl-, N-cycloalkyl-, and N-arylcarbamates were synthesized by reaction of the correspondingamines with dimethyl carbonate in the presence of binder-free FeHY zeolite. Theoptimal conditions (reactant ratio, amount of the catalyst, temperature,reaction time) were found to afford the target products with high yields.
Synthesis of: N -methylated amines from acyl azides using methanol
Chakrabarti, Kaushik,Dutta, Kuheli,Kundu, Sabuj
, p. 5891 - 5896 (2020/08/21)
The transformation of acyl azide derivatives into N-methylamines was developed using methanol as the C1 source via the one-pot Curtius rearrangement and borrowing hydrogen methodology. Following this protocol, various functionalised N-methylated amines were synthesized using the (NNN)Ru(ii) complex from carboxylic acids via an acyl azide intermediate. Several kinetic studies and DFT calculations were carried out to support the mechanism and also to determine the role of the Ru(ii) complex and base in this transformation.
Calcium carbide as a dehydrating agent for the synthesis of carbamates, glycerol carbonate, and cyclic carbonates from carbon dioxide
Choi, Jun-Chul,Fujitani, Tadahiro,Fukaya, Norihisa,Lin, Xiao-Tao,Sato, Kazuhiko,Yuan, Hao-Yu,Zhang, Qiao
, p. 4231 - 4239 (2020/10/02)
Carbon dioxide (CO2) is a nontoxic and inexpensive C1 building block, which can be used for the synthesis of valuable chemicals such as aromatic carbamates from anilines and methanol (MeOH), glycerol carbonate from glycerol, and cyclic carbonates from diols. However, these reactions generate water as the byproduct and suffer from thermodynamic limits, which lead to low yields. Calcium carbide (CaC2) is a renewable chemical, which can be recycled from calcium that is abundant in the Earth's crust. Furthermore, CaC2 rapidly reacts with water. In this work, we used CaC2 as a dehydrating agent for the direct synthesis of carbamates (including polyurethane precursors) from amines, CO2, and MeOH. All reagents were commercially available. In addition, CaC2 was employed for the synthesis of glycerol carbonate from glycerol and CO2 with a zinc catalyst and N-donor ligand. A similar protocol was applied to synthesize cyclic carbonates from diols and CO2.
CuSe2/CeO2 as a novel heterogeneous catalyst for reductive carbonylation of nitroarenes for generating urethanes
Tran, Anh Vy,Nguyen, Thanh Tung,Lee, Hye Jin,Bae, Se Won,Baek, Jayeon,Kim, Hoon Sik,Kim, Yong Jin
, (2019/09/19)
The reaction of CuCl2, SeO2, and cetyltrimethylammonium bromide (CTAB) under the CO pressure in methanol produce a black solid, which is identified as cupric diselenide, CuIISe2 using various spectroscopic analyses. Impregnation of 5 wt% of CuSe2 onto CeO2 resulted in much more enhanced catalytic activity due to the uniform and highly dispersed particle. The reductive carbonylation of nitrobenzene (NB) as a model substrate has been examined in the presence of the CuSe2/CeO2 as a single component heterogeneous catalyst, which is found to exhibit excellent catalytic activity for generating methyl-N-phenyl carbamate (MPC) in a highly selective fashion. The effects of various reaction parameters such as temperature, pressure, and reaction time have been investigated. A plausible reaction mechanism using this cheap heterogeneous catalyst is also presented, especially invoking the importance of CuSe2(μ-CO) species.
Interaction of dimethyl carbonate with anilines in the presence of potassium methylate: Kinetics and the role of the base
Mantrov, Sergey N.,Gordeev, Dmitry A.,Dashkin, Ratmir R.,Nefedov, Pavel A.,Seferyan, Mary A.
, p. 777 - 785 (2019/08/07)
The kinetic patterns of the reaction between dimethyl carbonate and anilines in the presence of a potassium methylate as a catalyst were studied. The mechanism of aminolysis was clarified, which includes the detachment of the proton from the amino group of aniline and the subsequent attack of the resulting anion on the carbonyl group of dimethyl carbonate. It is shown that when the reaction occurs in the dimethyl carbonate-methanol 3:1 system, the process can be described as an irreversible first-order reaction in the aniline though the target reaction is complicated by side interaction between potassium methylate and dimethyl carbonate. The rate constants of the target reaction with substituted anilines and of the side reaction in the temperature range of 70-90°C were determined. It is shown that the influence of the substituent on the reaction rate is described by the Hammett equation, with the constant of the reaction series being positive and the best correlation being achieved for ??-scale. The results obtained are consistent with the proposed mechanism of the reaction and are explained by the facilitation of the aniline deprotonation with increasing acceptor properties of the substituent. Effective activation energies for the reaction of various anilines with dimethyl carbonate are found.
