7160-01-2Relevant academic research and scientific papers
Living Polymerization of 2-Ethylthio-2-oxazoline and Postpolymerization Diversification
Wu, You-Chi Mason,Swager, Timothy M.
supporting information, p. 12498 - 12501 (2019/09/04)
The postpolymerization modification of polymers produced by living polymerization is an attractive method to create precision nanomaterials. We describe the living cationic ring-opening polymerization of a 2-alkylthio-2-oxazoline to furnish a polythiocarbamate. The polythiocarbamate is activated toward substitution by N- and S-nucleophiles via oxidation of the S to an SO2. Mild substitution conditions provide broad functional group tolerance, constituting a versatile postpolymerization modification platform with access to a diversity of polyureas and polythiocarbamates. We further demonstrate the utility of this strategy by synthesizing and functionalizing block copolymers.
Cu(II)-Catalyzed Ortho-C-H Nitration of Aryl Ureas by C-H Functionalization
Wang, Chun-Meng,Tang, Kai-Xiang,Gao, Tian-Hong,Chen, Lin,Sun, Li-Ping
, p. 8315 - 8321 (2018/07/15)
A novel protocol for the aromatic ortho C-H nitration of aryl ureas with Fe(NO3)3·9H2O is developed. The reaction utilizes CuCl2·2H2O as catalyst and p-TSA as additive, showing good functional group tolerance and furnishing the desired products in moderate to excellent yields.
One-pot synthesis of 2,3-difunctionalized indoles: Via Rh(III)-catalyzed carbenoid insertion C-H activation/cyclization
Lv, Honggui,Shi, Jingjing,Wu, Bo,Guo, Yujuan,Huang, Junjun,Yi, Wei
supporting information, p. 8054 - 8058 (2017/10/13)
Reported herein is the first Rh(iii)-catalyzed carbenoid insertion C-H activation/cyclization of N-arylureas and α-diazo β-keto esters. The redox-neutral reaction has the following features: good to excellent yields, broad substrate/functional group tolerance, exclusive regioselectivity, and no need for additional oxidants or additives, which render this methodology as a more efficient and versatile alternative to the existing methods for the synthesis of 2,3-difunctionalized indoles.
Transition Metal-Free Carbazole Synthesis from Arylureas and Cyclohexanones
Wu, Jun,Xie, Yanjun,Chen, Xiangui,Deng, Guo-Jun
supporting information, p. 3206 - 3211 (2016/10/21)
An efficient strategy for carbazole synthesis from arylureas and cyclohexanones under transition metal-free conditions has been developed. The combined use of potassium iodide and iodine could significantly improve the reaction efficiency to provide 2,6-disubstituted 9-arylcarbazoles in moderate to good yields. In this kind of transformation, the whole carbazole moiety (except the nitrogen atom) comes from two equivalents of cyclohexanones. (Figure presented.).
Merging C-H activation and alkene difunctionalization at room temperature: A palladium-catalyzed divergent synthesis of indoles and indolines
Manna, Manash Kumar,Hossian, Asik,Jana, Ranjan
supporting information, p. 672 - 675 (2015/03/04)
A palladium-catalyzed 1,2-carboamination through C-H activation at room temperature is reported for the synthesis of 2-arylindoles, and indolines from readily available, inexpensive aryl ureas and vinyl arenes. The reaction initiates with a urea-directed electrophilic ortho palladation, alkene insertion, and ?2-hydride elimination sequences to provide the Fujiwara-Moritani arylation product. Subsequently, aza-Wacker cyclization, and ?2-hydride elimination provide the 2-arylindoles in high yields. Intercepting the common -alkyl-Pd intermediate, corresponding indolines are also achieved. The indoline formation is attributed to the generation of stabilized, cationic -benzyl-Pd species to suppress ?2-hydride elimination.
Rhodium(iii)-catalysed aerobic synthesis of highly functionalized indoles from N-arylurea under mild conditions through C-H activation
Kathiravan, Subban,Nicholls, Ian A.
supporting information, p. 14964 - 14967 (2014/12/11)
A Rh(iii) catalysed amino arylation of alkynes using copper as the terminal oxidant for regeneration of the catalytically active species under aerobic conditions is described. This novel C-H activation reaction was applied to the synthesis of a wide range of substituted indoles from N-arylureas.
Facile dehalogenation of halogenated anilines and their derivatives using Al-Ni alloy in alkaline aqueous solution
Weidlich, Tomas,Prokes, Lubomir
experimental part, p. 590 - 597 (2012/04/10)
This article describes the simple hydrodehalogenation of halogenated anilines and their derivatives by the action of Raney aluminium-nickel alloy in aqueous alkaline solution at room temperature. The reaction course was monitored by means of 1H nuclear magnetic resonance (NMR) spectroscopy and GC-MS spectra. The effect of Al and Ni and the nature and quantity of the base for effective hydrodehalogenation were studied. The possibility of lowering Al content more than 500 times and Ni content more than 10 times in the filtered mother liquor by a dehalogenation procedure was tested using precipitation. The reduction method described was satisfactorily proved for dehalogenation of polyhalogenated anilines in the multiphase dimethoxymethane/aqueous NaOH/Al-Ni reaction mixture. Dehalogenation under multi-phase conditions was demonstrated for the preparation of ortho-alkylated anilines from simply available 2-substituted-4-chloroanilines. Versita Sp. z o.o.
Preparation of N,N-Dimethyl-N′-arylureas using S,S-dimethyl dithio-carbonate as a carbonylating reagent
Degani, Iacopo,Fochi, Rita,Magistris, Claudio,Migliaccio, Mara
experimental part, p. 801 - 808 (2009/08/07)
A new, general method for the preparation of N,N-di-methyl-N′- arylureas using S,S-dimethyl dithiocarbonate as a phosgene substitute is reported. The method has been set up according to four procedures, all including three steps: (1) reaction of S,S-di- methyl dithiocarbonate with dimethylamine to give S-methyl N,N-dimethylthiocarbamate; (2) halogenation with various halogenating reagents (chlorine, methanesulfenyl chloride, bromine, and meth-anesulfenyl bromide) to give N,N-dimethylcarbamoyl chloride or bromide; (3) in situ reaction with primary arylamines. All the target products were obtained in high yields (85-98%; 16 reactions, average yield 93%) and with high purity. Also noteworthy is the recovery of byproducts of industrial interest, namely methanethiol and dimethyl disulfide, with complete exploitation of the reagent S,S- dimethyl dithiocarbonate. Georg Thieme Verlag Stuttgart.
Distinct reactivity of Pd(OTs)2: The intermolecular Pd(II)-catalyzed 1,2-carboamination of dienes
Houlden, Chris E.,Bailey, Chris D.,Ford, J. Gair,Gagne, Michel R.,Lloyd-Jones, Guy C.,Booker-Milburn, Kevin I.
supporting information; experimental part, p. 10066 - 10067 (2009/02/04)
A Pd-catalyzed intermolecular 1,2-carboamination route to indolines from N-aryl ureas and 1,3-dienes that proceeds under mild conditions in relatively nonacidic media, is presented. The in situ generation, or preformation, of a palladium tosylate emerges as a key parameter in gaining the requisite reactivity for the C-H insertion/carbopalladation/nucleophilic displacement process. Copyright
A Facile and High-yielding Preparation of 1-Aryl-3,3-dialkylureas
Xian, Ming,Lu, Jianming,Zhu, Xiaoqing,Mu, Linjing,Cheng, Jin-Pei
, p. 442 - 443 (2007/10/03)
A convenient procedure for the preparation of 1-aryl-3,3-dialkylureas using bis(trichoromethyl) carbonate ('triphosgene') is described.
