39896-97-4Relevant academic research and scientific papers
Selective N,N-dibenzylation of primary aliphatic amines with dibenzyl carbonate in the presence of phosphonium salts
Loris, Alessandro,Perosa, Alvise,Selva, Maurizio,Tundo, Pietro
, p. 3953 - 3956 (2004)
In the presence of catalytic amounts of tetraalkylphosphonium salts and under solventless conditions, primary aliphatic amines (RNH2: R = PhCH2, Ph(CH2)2, n-decyl, and 1-naphthylmethyl) are efficiently N-benzylated to the corresponding RN(CH2Ph) 2, using dibenzyl carbonate as the benzylating reagent. Compared to the reaction run without salt, where the competitive formation of the benzyl carbamate is favored, the phosphonium salt promotes high selectivity toward the benzylated amine and an increase of the reaction rate as well. However, in a single case explored for an amino acidic compound, namely 4-(aminomethyl) benzoic acid [4-(NH2CH2)C6H4CO 2H], both N,N-dibenzylation and esterification of the acid group were observed. Analysis of the IR vibrational modes of benzylamine in the presence of tetrabutylphosphonium bromide supports the hypothesis that this enhanced selectivity may be due to an acid-base interaction between the salt and the amine, which increases the steric bulk of the amine and favors attack of the nucleophile on the less hindered alkyl terminus of dibenzyl carbonate.
Reductive cleavage of N - O bonds in hydroxylamine and hydroxamic acid derivatives using Sml2/THF
Keck, Gary E.,McHardy, Stanton F.,Wager, Travis T.
, p. 7419 - 7422 (1995)
The title reaction affords a general method for the reductive cleavage of N - O bonds, and is successful in some cases where established methods fail.
Design, synthesis and SAR of antitubercular benzylpiperazine ureas
Satish, Sohal,Chitral, Rohan,Kori, Amitkumar,Sharma, Basantkumar,Puttur, Jayashree,Khan, Afreen A.,Desle, Deepali,Raikuvar, Kavita,Korkegian, Aaron,Martis, Elvis A. F.,Iyer, Krishna R.,Coutinho, Evans C.,Parish, Tanya,Nandan, Santosh
, (2021/01/04)
Abstract: N-furfuryl piperazine ureas disclosed by scientists at GSK Tres Cantos were chosen as antimycobacterial hits from a phenotypic whole-cell screen. Bioisosteric replacement of the furan ring in the GSK Tres Cantos molecules with a phenyl ring led to molecule (I) with an MIC of 1?μM against Mtb H37Rv, low cellular toxicity (HepG2 IC50 ~ 80?μM), good DMPK properties and specificity for Mtb. With the aim of delineating the SAR associated with (I), fifty-five analogs were synthesized and screened against Mtb. The SAR suggests that the piperazine ring, benzyl urea and piperonyl moieties are essential signatures of this series. Active compounds in this series are metabolically stable, have low cellular toxicity and are valuable leads for optimization. Molecular docking suggests these molecules occupy the Q0 site of QcrB like Q203. Graphic Abstract: Bioisosteric replacement of N-furfuryl piperazine-1-carboxamides yielded molecule (I) a novel lead with satisfactory PD, metabolism, and toxicity profiles.[Figure not available: see fulltext.]
Interrupted aza-Wittig reactions using iminophosphoranes to synthesize 11C-carbonyls
Ismailani, Uzair S.,Munch, Maxime,Mair, Braeden A.,Rotstein, Benjamin H.
supporting information, p. 5266 - 5269 (2021/06/06)
A direct CO2-fixation methodology couples structurally diverse iminophosphoranes with various nucleophiles to synthesize ureas, carbamates, thiocarbamates, and amides, and is amenable for 11C radiolabeling. This methodology is practical, as demonstrated by the synthesis of >35 products and isolation of the molecular imaging radiopharmaceuticals [11C]URB694 and [11C]glibenclamide. This journal is
O-Alkyl S-(Pyridin-2-yl)carbonothiolates: Operationally Simple and Highly Nitrogen-Selective Reagents for Alkoxy Carbonylation of Amino Groups
Hashimoto, Yoshimitsu,Morita, Nobuyoshi,Suzuki, Tomoyuki,Tamura, Osamu,Tanaka, Kosaku
, p. 899 - 902 (2020/05/28)
Amino groups are selectively protected in good yields by reaction with O-Alkyl S-(pyridin-2-yl)carbonothiolates in an appropriate solvent at room temperature in air. Even glucosamine, which contains multiple hydroxyl groups, is selectively N-protected in methanol.
CaI2-Catalyzed direct transformation of: N -Alloc-, N -Troc-, and N -Cbz-protected amines to asymmetrical ureas
Tran, Van Hieu,Kim, Hee-Kwon
, p. 14093 - 14101 (2019/09/18)
A novel and facile CaI2-catalyzed direct synthesis of asymmetrical ureas from N-Alloc-, N-Troc-, and N-Cbz-protected amines is developed. In this study, the efficient reaction of Alloc-, Troc-, and Cbz-carbamates with amines in the presence of catalytic CaI2 successfully generated various asymmetrical ureas. This catalytic synthetic procedure provided the desired ureas via reactions of these protected aromatic and aliphatic amines with various amines in high yields without side products. This suggests that novel direct synthesis of ureas from Alloc-, Troc-, and Cbz-carbamates can be a promising approach for the synthesis of useful ureas.
Carbamate Synthesis Using a Shelf-Stable and Renewable C1 Reactant
Dobi, Zoltán,Reddy, B. Narendraprasad,Renders, Evelien,Van Raemdonck, Laurent,Mensch, Carl,De Smet, Gilles,Chen, Chen,Bheeter, Charles,Sergeyev, Sergey,Herrebout, Wouter A.,Maes, Bert U. W.
, p. 3103 - 3114 (2019/06/24)
4-Propylcatechol carbonate is a shelf-stable, renewable C1 reactant. It is easily prepared from renewable 4-propylcatechol (derived from wood) and dimethyl carbonate (derived from CO2) using a reactive distillation system. In this work, the 4-propylcatechol carbonate is used for the two-step synthesis of carbamates under mild reaction conditions. In the first step, 4-propylcatechol carbonate is treated with an alcohol at 50–80 °C in the presence of a Lewis acid catalyst, such as Zn(OAc)2?2 H2O. With liquid alcohols, no solvent is used and with solid alcohols 2-methyltetrahydrofuran is used as solvent. In the second step, the alkyl 2-hydroxy-propylphenyl carbonate intermediates obtained react with amines at room temperature in 2-methyltetrahydrofuran, forming the target carbamates and the byproduct 4-propylcatechol, which can be recycled into a carbonate reactant.
METHOD OF CONVERTING CARBON DIOXIDE INTO CARBONYL COMPOUNDS
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Page/Page column 15, (2019/05/02)
The present invention provides a method for fixing carbon dioxide gas as a carbonyl compound represented by formula (3) as depicted by Figure 1 and comprising, purging of carbon dioxide in a solution of a nucleophile represented by the formula (1) in presence of a solvent at a temperature ranging from -40 Degree Celsius to 35 Degree Celsius, followed by adding a reagent at temperature ranging from -40 degree to 35 degree and thereafter adding another nucleophile represented by the formula (2) to obtain carbonyl compound represented by formula (3). The present invention can be advantageously used to obtain commercially important carbonyl compounds and clean unwanted carbon dioxide gas from the atmosphere and industrial effluents.
Reductions of Imines Using Zirconocene Chloride Hydride
Vargová, Denisa,Mudráková, Brigita,Némethová, Ivana,?ebesta, Radovan
, p. 7606 - 7612 (2019/12/03)
Herein, we describe the fast, chemoselective, and clean reduction of imines with zirconocene chloride hydride. The reaction works well on aromatic and enolizable aliphatic aldimines, as well as ketimines. A range of N-protecting groups and various functio
One stone two birds: Cobalt-catalyzed in situ generation of isocyanates and benzyl alcohols for the synthesis of N-aryl carbamates
Li, Sida,Khan, Ruhima,Zhang, Xia,Yang, Yong,Wang, Zheting,Zhan, Yong,Dai, Yuze,Liu, Yue-E,Fan, Baomin
, p. 5891 - 5896 (2019/06/24)
An efficient method for the synthesis of N-aryl carbamates from N-Boc-protected amines has been developed. The cobalt-catalyzed in situ generation of isocyanates from N-Boc-protected amines and benzyl alcohols from benzyl formates has been achieved for the first time, which in turn furnished the corresponding benzyl carbamates in moderate to high yields. The reaction was catalyzed by CoI2 with tris-(4-dimethylaminophenyl)-phosphine as the ligand and zinc powder as the reductant. The developed reaction conditions were found to be compatible for aromatic amines with both electron-donating and -withdrawing substituents.
