41429-37-2Relevant academic research and scientific papers
Sulfonium Salts as Alkylating Agents for Palladium-Catalyzed Direct Ortho Alkylation of Anilides and Aromatic Ureas
Simkó, Dániel Cs.,Elekes, Péter,Pázmándi, Vivien,Novák, Zoltán
supporting information, p. 676 - 679 (2018/02/09)
A novel method for the ortho alkylation of acetanilide and aromatic urea derivatives via C-H activation was developed. Alkyl dibenzothiophenium salts are considered to be new reagents for the palladium-catalyzed C-H activation reaction, which enables the transfer of methyl and other alkyl groups from the sulfonium salt to the aniline derivatives under mild catalytic conditions.
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.
Cationic Pd(II)-catalyzed C-H activation/cross-coupling reactions at room temperature: Synthetic and mechanistic studies
Nishikata, Takashi,Abela, Alexander R.,Huang, Shenlin,Lipshutz, Bruce H.
supporting information, p. 1040 - 1064 (2016/07/06)
Cationic palladium(II) complexes have been found to be highly reactive towards aromatic C-H activation of arylureas at room temperature. A commercially available catalyst [Pd(MeCN)4](BF4)2 or a nitrile-free cationic palladium(II) complex generated in situ from the reaction of Pd(OAc)2 and HBF4, effectively catalyzes C-H activation/cross-coupling reactions between aryl iodides, arylboronic acids and acrylates under milder conditions than those previously reported. The nature of the directing group was found to be critical for achieving room temperature conditions, with the urea moiety the most effective in promoting facile coupling reactions at an ortho C-H position. This methodology has been utilized in a streamlined and efficient synthesis of boscalid, an agent produced on the kiloton scale annually and used to control a range of plant pathogens in broadacre and horticultural crops. Mechanistic investigations led to a proposed catalytic cycle involving three steps: (1) C-H activation to generate a cationic palladacycle; (2) reaction of the cationic palladacycle with an aryl iodide, arylboronic acid or acrylate, and (3) regeneration of the active cationic palladium catalyst. The reaction between a cationic palladium(II) complex and arylurea allowed the formation and isolation of the corresponding palladacycle intermediate, characterized by X-ray analysis. Roles of various additives in the stepwise process have also been studied.
Lateral lithiation and substitution of N'-(2-methylphenyl)- N,N-dimethylurea
Smith, Keith,El-Hiti, Gamal A.,Al-Mansury, Sadiq A.,Alshammari, Mohammed B.,Balakit, Asim A.
, p. 365 - 375 (2014/12/11)
Lithiation of N'-(2-methylphenyl)-N,N-dimethylurea with three molar equivalents of tert-butyllithium at -40 to -30 °C takes place on the nitrogen and on the methyl group at position 2 of the phenyl group. The lithium intermediate thus obtained reacts with a variety of electrophiles to give the corresponding side-chain substituted derivatives in high yields.
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.
The vinyl moiety as a handle for regiocontrol in the preparation of unsymmetrical 2,3-aliphatic-substituted indoles and pyrroles
Huestis, Malcolm P.,Chan, Lina,Stuart, David R.,Fagnou, Keith
supporting information; experimental part, p. 1338 - 1341 (2011/04/21)
Rho-Rho-Rho your boat: A rhodium catalyst effects the regioselective oxidative coupling of enynes with N-aryl ureas (X=NR2) and N-vinylacetamides (X=C(O)Me), affording the corresponding 2-alkenylindoles and 2-alkenylpyrroles in good yield. Simple hydrogenation delivers the C2/C3-aliphatic-substituted indole or pyrrole (see scheme).
Comparative catalytic C-H vs. C-Si activation of arenes with Pd complexes directed by urea or amide groups
Rauf, Waqar,Thompson, Amber L.,Brown, John M.
supporting information; experimental part, p. 3874 - 3876 (2010/01/06)
Analysis of regiocontrol in Pd-catalysed C-H activation leads to observations of aryltrimethylsilyl activation and to superior results with urea-based substrates.
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.
Process for the preparation of trisubstituted ureas
-
, (2008/06/13)
The present invention provides a process for preparing a trisubstituted urea of the general formula: in which R is a substituted or unsubstituted mono-, di- or polyvalent aromatic radical, R' is a substituted or unsubstituted monovalent aliphatic or aromatic radical and R is a substituted or unsubstituted monovalent aliphatic radical or R' and R together represent a substituted or unsubstituted divalent radical in which at least one of the two carbon atoms adjoining the nitrogen atom of the urea is aliphatic, and n is an integer, wherein an aromatic nitrocompound of the general formula:--R(NO2)n or an aromatic nitrosocompound of the general formula:--R(NO)n is allowed to react with a secondary ammonium N,N-disubstituted thiolcarbamate of the general formula: or with a mixture of a secondary amine of the general formula:--R'R NH and carbon monoxide and sulphur, carbon monoxide and hydrogen sulphide, or carbonyl sulphide, or with a mixture of a secondary ammonium sulphide or hydrosulphide of the general formula: or and carbon monoxide.
