- Cp2TiCl2-CATALYZED REACTION OF GRIGNARD REAGENTS WITH ISOCYANATES, FORMATION OF REDUCTION-COUPLING PRODUCT OF ISOCYANATES
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Phenylisocyanate and phenylthioisocyanate react with Grignard reagents in the presence of a small amount of Cp2TiCl2 at room temperature to afford reduction-coupling products, N-methyl-N,N'-diphenylurea and N-methyl-N,N'-diphenylthiourea.
- Zhang, Yongmin,Jiang, Jinlong,Zhang, Zhangxi
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- 2,2,2-Trifluroenthanol promoted synthesis of unsymmetrical ureas from dioxazolones and amines via tandem lossen rearrangement/condensation process
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A 2,2,2-trifluroenthanol (TFE) promoted synthesis of unsymmetric ureas was described. This approach enabled the construction of a variety of ureas from the readily prepared and easy-to-handle dioxazolones and amines via tandem Lossen rearrangement/condensation process. The reaction featured mild conditions for the urea synthesis under metal-free conditions, which was successively applied in the scale-up synthesis of herbicides Monuro and Isoproturon.
- Li, Jian,He, Wang,Lei, Pan,Song, Jiacheng,Huo, Jiyou,Wei, Hongbo,Bai, Hongjin,Xie, Weiqing
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supporting information
p. 3590 - 3600
(2021/10/07)
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- Hydroamination and Hydrophosphination of Isocyanates/Isothiocyanates under Catalyst-Free Conditions
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Symmetrical and unsymmetrical N,N’-disubstituted as well as trisubstituted ureas/thioureas by the hydroamination of isocyanates/isothiocyanates, and various phosphathioureas by the hydrophosphination of isothiocyanates have been synthesized in good to excellent yields under catalyst-free and mild conditions. This protocol is also applicable for the efficient synthesis of chiral ureas and thioureas and common herbicides, such as fenuron and monuron.
- Zhu, Xiancui,Xu, Mengchen,Sun, Jinrong,Guo, Dianjun,Zhang, Yiwei,Zhou, Shuangliu,Wang, Shaowu
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p. 5213 - 5218
(2021/10/19)
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- Preparation method of amide derivative
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The invention provides a preparation method of an amide derivative. The method comprises the following steps: taking hydroxamic acid and an amine or thiol compound as raw materials, sequentially adding alkali and a solvent, carrying out a reaction for 2-7 hours at the temperature of 25-50 DEG C in an SO2F2 atmosphere, and after the reaction is finished, carrying out aftertreatment on a reaction solution to obtain the asymmetric urea compound or thiocarbamate compound. According to the invention, cheap, easily available and environment-friendly SO2F2 is used as an accelerant to efficiently promote the generation of isocyanate intermediates and form C-N and C-S bonds. The generation of isocyanate avoids the use of a large amount of halogen or azide dangerous reagents, so that the compound can be used as a green substitute for standard treatment conditions in Curtius rearrangement and Hofmann rearrangement reactions. The substrate is wide in applicability, and the corresponding asymmetricurea and thiocarbamate compounds can be obtained at a relatively good yield. The operation process is simple and suitable for large-scale preparation.
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Paragraph 0030-0034
(2020/05/30)
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- A Novel C–N Migration Rearrangement Based on N–F Compounds for the Synthesis of N-Alkyl Diaryl Ureas
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A novel rearrangement reaction based on the structure of N-fluoro-N-(phenylsulfonyl) benzamides (FPSBA) was developed. In the presence of base, unsymmetrical N-alkyl diaryl ureas were obtained in good yields which were accomplished through secondary alkyl phenylamines initiated 1,2-phenyl-shift migration rearrangement of N-fluoro-N-(phenylsulfonyl) benzamides. The reaction was carried out without using traditional, highly toxic reagents and noble metals. Whereas without rearrangement occurrence for primary phenylamines and aliphatic amines, normal amides and N-(phenylsulfonyl) benzamides were afforded respectively. Nitrene and phenyl isocyanate included process were prevented and a secondary alkyl phenylamine initiated vicinal SN2' reaction occurred. This rearrangement reaction features an interesting reaction mechanism, mild reaction conditions, simple operation, and useful products.
- Zhao, Yi-Xiao,Xie, Tian,Yang, San-Ke,Yang, Xian-Jin
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p. 437 - 445
(2020/01/22)
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- A Palladium-Catalyzed Domino Procedure for the Synthesis of Unsymmetrical Ureas
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A palladium-catalyzed carbonylative procedure for the synthesis of unsymmetrical ureas has been developed. This one-pot one-step cascade procedure is consisted by three individual processes: carbonylation, Curtius rearrangement, and nucleophilic addition. A series of unsymmetrical ureas were prepared from easily available aryl iodides and amines in moderate to excellent yields. This procedure provides a convenient and practical approach for unsymmetrical urea synthesis. (Figure presented.).
- Chen, Bo,Peng, Jin-Bao,Ying, Jun,Qi, Xinxin,Wu, Xiao-Feng
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supporting information
p. 2820 - 2824
(2018/08/17)
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- An efficient one-pot synthesis of N,N′-disubstituted phenylureas and N-aryl carbamates using hydroxylamine-O-sulfonic acid
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We have developed an efficient one-pot method for the microwave-assisted synthesis of ureas and carbamates via a proposed Lossen rearrangement. Herein we report the first examples of the direct conversion of benzoyl chlorides into N,N′-disubstituted ureas and N-aryl carbamates using hydroxylamine-O-sulfonic acid as reagent. Using our general method, we have produced 11 examples of N,N′-disubstituted phenylureas in yields up to 95% using various substituted anilines, and primary and secondary amines. Additionally, we were able to generate a series of N-aryl carbamates in moderate yields using primary, secondary and tertiary alcohols.
- Bao, Jennifer,Kuik, Dale,Tranmer, Geoffrey K.
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supporting information
p. 5546 - 5553
(2018/06/12)
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- I2-Mediated transition-metal-free aromatic C-H amination for the synthesis of benzimidazol-2-ones and related heterocycles
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A practical iodine-mediated direct aromatic C-H amination reaction has been established for benzimidazol-2-one synthesis under transition-metal-free conditions. The required 1,3-diarylurea substrates are readily accessible by the addition of N-substituted arylamines to the corresponding isocyanates. This versatile and operationally simple synthetic process is broadly applicable to a wide range of 1,3-diarylureas and provides facile access to benzimidazol-2-ones and related heterocycles. Moreover, the present C-H amination reaction can also be performed directly from disubstituted amines and isocyanates without the purification of the urea intermediates in a scalable fashion.
- Meng, Yinggao,Wang, Bingnan,Ren, Linning,Zhao, Qiongli,Yu, Wenquan,Chang, Junbiao
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p. 13790 - 13796
(2018/08/21)
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- Synthesis of ureas in the bio-alternative solvent Cyrene
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Cyrene as a bio-alternative solvent: a highly efficient, waste minimizing protocol for the synthesis of ureas from isocyanates and secondary amines in the bio-available solvent Cyrene is reported. This method eliminated the use of toxic solvents, such as
- Mistry, Liam,Mapesa, Kopano,Bousfield, Thomas W.,Camp, Jason E.
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supporting information
p. 2123 - 2128
(2017/07/24)
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- Hydroxoiridium-Catalyzed Hydroalkylation of Terminal Alkenes with Ureas by C(sp3)?H Bond Activation
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Direct alkylation of a methyl group, on di- and trisubstituted ureas, with terminal alkenes by C(sp3)?H bond activation proceeded in the presence of a hydroxoiridium/bisphosphine catalyst to give high yields of the corresponding addition products. The hydroxoiridium/bisphosphine complex generates an amidoiridium intermediate by reaction with ureas having an N?H bond.
- Yamauchi, Daisuke,Nishimura, Takahiro,Yorimitsu, Hideki
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supporting information
p. 7200 - 7204
(2017/06/13)
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- Preparation method for alkyl/benzyl/aryl urea compounds through heterogeneous-phase catalysis
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The invention discloses a preparation method for formula (I) compounds, and the compounds are obtained by reacting a formula (II) compound with a formula (III) compound in a solvent in carbon monoxide atmosphere under catalysis of a heterogeneous-phase pa
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Paragraph 0063-0071; 0072; 0073; 0074; 0076; 0078; 0082
(2016/10/09)
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- Pd(II)/Ag(I)-Promoted One-Pot Synthesis of Cyclic Ureas from (Hetero)Aromatic Amines and Isocyanates
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A simple and facile one-pot reaction has been developed to afford a diverse range of N,N′-disubstituted benzimidazolones and imidazopyridinones containing two differently substituted N atoms. A cooperative Pd(II)/Ag(I) system promotes the sequential addition/intramolecular C-H amidation reaction of (hetero)aromatic amines and isocyanates, leading to the formation of two C-N bonds. A mechanism involving radical intermediates generated by single-electron transfer (SET) in the presence of a Ag2CO3 oxidant and Pd(OAc)2 Lewis acid is proposed. This protocol offers an operationally easy, simple, and robust approach with the use of readily available starting materials, good functional group tolerance, and high efficiency.
- Youn, So Won,Kim, Yi Hyun
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p. 6140 - 6143
(2016/12/09)
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- Pd/C Catalyzed Carbonylation of Azides in the Presence of Amines
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A facile and efficient Pd/C-catalyzed carbonylation of both aliphatic and aromatic azides in the presence of amines is reported. Serving as the widely existed fragments in an array of biological pharmaceuticals, functionalized unsymmetrical ureas were str
- Zhao, Jin,Li, Zongyang,Yan, Shuaihu,Xu, Shiyang,Wang, Ming-An,Fu, Bin,Zhang, Zhenhua
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supporting information
p. 1736 - 1739
(2016/05/19)
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- One-pot synthesis of trisubstituted ureas from achloroaldoxime O-methanesulfonates and secondary amines
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Trisubstituted ureas can be synthesized in a one-pot fashion from bench-stable a-chloroaldoxime Omethanesulfonates and secondary amines under mild reaction conditions. Two practical protocols have been developed to achieve various urea syntheses from both secondary aromatic amines and aliphatic amines.
- Kaeobamrung, Juthanat,Lanui, Asan,Mahawong, Sirinad,Duangmak, Witthawin,Rukachaisirikul, Vatcharin
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p. 58587 - 58594
(2018/02/19)
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- Selective N-methylation of aliphatic amines with CO2 and hydrosilanes using nickel-phosphine catalysts
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A method using CO2 and PhSiH3 for the methylation of primary and secondary aliphatic amines catalyzed by Ni (0) complexes was developed, selectively producing the monomethylated products in moderate to good yields. For that purpose, two catalysts were used: [(dippe)Ni(μ-H)]2 and the commercially available Ni(COD)2/dcype, both of which were rather efficient in this process. With a slight experimental modification, the reaction allowed the production of monomethylated ureas in good yields by using low amounts of PhSiH3. On the basis of the experimental results, we propose a possible reaction mechanism for the formation of the new C-N bond.
- Gonzlez-Sebastin, Lucero,Flores-Alamo, Marcos,Garca, Juventino J.
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p. 763 - 769
(2015/05/12)
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- Copper-catalyzed one-pot synthesis of unsymmetrical arylurea derivatives via tandem reaction of diaryliodonium salts with N -arylcyanamide
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An efficient "one-pot" approach to multiple substituted ureas from N-arylcyanamide and diaryliodonium salts has been presented. The two-step procedure involved the weak base-promoted chemoselective arylation of secondary amines with diaryliodonium and Cu-catalyzed nucleophilic addition of N-arylcyanamide with second diaryliodonium. The diverse unsymmetrical arylureas were obtained in up to 91% yield for 29 examples.
- Li, Pengfei,Cheng, Guolin,Zhang, Hong,Xu, Xianxiang,Gao, Jingyuan,Cui, Xiuling
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p. 8156 - 8162
(2015/03/18)
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- Catalytic oxidative carbonylation of arylamines to ureas with W(CO) 6/I2 as catalyst
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The oxidative carbonylation of aniline to N,N'-diphenylurea was carried out by using W(CO)6 as the catalyst, I2 as the oxidant, CO as the carbonyl source and 4-(dimethylamino)pyridine (DMAP) as base. The reaction conditions were optimized with respect to different bases, molar ratio of DMAP/iodine, temperature, time, and CO pressure. Various p-substituted arylamines can be converted into the respective symmetrical and unsymmetrical N,N'-disubstituted ureas in moderate to good yields. The reaction demonstrated broad tolerance of functionality.
- Zhang, Li,Darko, Ampofo K.,Johns, Jennifer I.,McElwee-White, Lisa
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experimental part
p. 6261 - 6268
(2011/12/04)
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- A facile, safe and inexpensive preparation of S -methyl arylcarbamothioates by methylthiocarbonylation of primary arylamines with O, S -dimethyl carbonodithioate
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O,S-Dimethyl carbonodithioate is proposed as a suitable and safely handled reagent that can be used in the methylthiocarbonylation of primary arylamines to give S-methyl arylcarbamothioates. Optimal conditions involved a one-step procedure that was carried out at 45C in a solvent-free system, in the presence of triethyl(methyl)ammonium S-methyl carbonodithioate as a reaction promoter. The title products were obtained pure in yields that, with one exception, varied between 72 and 91% (average yield of the 12 considered examples was 83%). The by-product S,S-dimethyl carbonodithioate is also a valuable reagent. Georg Thieme Verlag Stuttgart · New York.
- Degani, Iacopo,Fochi, Rita,Magistris, Claudio
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experimental part
p. 1113 - 1122
(2010/05/19)
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- The first aminimide synthesis from benzoyl azide and pyridine
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Irradiation of benzoyl azide 1 at 254 nm in the presence of some amines produces aminimides: in the presence of pyridine the aminimide 13 can be isolated in 41% yield; in the presence of N,N-dimethylaniline a CH insertion product 7 is obtained via an intermediate aminimide 12. This is the first reported synthesis of aminimides from a benzoyl azide. CSIRO 2007.
- Capuano, Ben,Crosby, Ian T.,Lloyd, Edward J.,Neve, Juliette E.
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p. 214 - 217
(2008/02/11)
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- Design, synthesis, and photodegradation of silicon-containing polyureas
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Novel N-phenyl aromatic polyureas containing bis[(N,N′- diphenylureylene)methyl]silane units in the skeleton were designed as a new type of photodegradable polymer. These materials were successfully prepared in 88-93% yields by copolymerization of bis(ani
- Hwu, Jih Ru,King, Ke Yung
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p. 3805 - 3815
(2007/10/03)
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- The direct conversion of carbamates to ureas using aluminum amides
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The conversion of carbamates into ureas using aluminum amide complexes is reported. This reaction is a convenient method to prepare bi-, tri- and tetra-substituted ureas from carbamate-protected primary or secondary amines by reaction with primary or secondary amines in the presence of stoichometric quantities of trimethylaluminum. A reactivity trend of the various carbamates was observed and methyl and benzyl carbamates were reacted selectively in the presence of t-butyl carbamates.
- Lee, Sang-Hyuep,Matsushita, Hana,Clapham, Bruce,Janda, Kim D.
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p. 3439 - 3443
(2007/10/03)
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- Reactions of dithiadiphosphetane disulfides with organonitrogen compounds
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The reactions of R1P(S)S2P(S)R1 (R1 = ferrocenyl) with a range of organic systems containing unsaturated C-N linkages have been studied. Thus treatment with dimethylcyanamide gives a 1,3,5,4-thiazaphosphorine 4-sulfide, whereas reaction with dicarbodiimides gives a thiazadiphosphetane. Furthermore reaction of diphenylurea gives a phenylthiazaphosphetane. Mechanisms for the reactions are proposed and the crystal structures of three selected examples are reported and discussed with reference to the steric effects of the reactants. These reactions provide a new entry into C-P-S-N heterocycles. Cyclic voltammetry studies on a range of ferrocenyl substituted heterocycles were also made. The Royal Society of Chemistry 1999.
- Foreman, Mark St. John,Mortimer, Roger J.,Slawin, Alexandra M. Z.,Woollins, J. Derek
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p. 3419 - 3430
(2007/10/03)
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- Extremely Reactive C=C Double Bonds, VI. - Tris(methylphenylamino)methane - The Chemistry of Orthoamides
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Reactions of the title compound 2 with sulfur, selenium, thiophenol, malononitrile, 1,3-indanedione, fluorenone hydrazone, phenylmagnesium bromide, bromine, thioacetic acid, N,N'-diphenylurea, oxalyl chloride, 9,9-dichloroxanthene, phenyl isocyanate, and stilbene dibromide are described and the mechanisms are discussed.The catalytic influence of 2 on the decomposition of 9-diazofluorene in xylene and mesitylene is discussed.
- Schoenberg, Alexander,Singer, Erich,Stephan, Werner
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p. 1581 - 1588
(2007/10/02)
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- Carbamoylation using the CO-containing Copper Complex derived from Lithium N-methylanilide
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Lithium N-methylanilide, prepared from N-methylaniline and n-butyllithium, readily absorbed CO at atmospheric pressure in the presence of cuprous iodide to produce a CO-containing copper complex.Treatment of this complex with organic halides gave the corresponding amides in good yields.Keywords - carbonylation; carbamoylation; carbon monoxide; cuprous iodide; lithium N-methylanilide
- Wakita, Yoshiaki,Kobayashi, Toshio,Maeda, Minoru,Kojima, Masaharu
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p. 3395 - 3398
(2007/10/02)
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