28170-54-9Relevant academic research and scientific papers
N,N -Dialkyl- N′ -Chlorosulfonyl Chloroformamidines in Heterocyclic Synthesis. Part XV.
Innes, Dylan,Perkins, Michael V.,Liepa, Andris J.,Francis, Craig L.
, p. 610 - 623 (2018/09/18)
N,N-Dimethyl-N′-chlorosulfonyl chloroformamidine 1a underwent reactions with various anilines. In addition to the benzo[e][1,2,4]thiadiazine dioxides 8, from 1,3-NCC bis-nucleophilic substitution and bis-anilino adducts 9, some unexpected products were fo
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.
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.
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.
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
Catalytic amide-mediated methyl transfer from silanes to alkenes in Fujiwara-Moritani oxidative coupling
Rauf, Waqar,Brown, John M.
supporting information; experimental part, p. 4228 - 4230 (2009/03/12)
(Chemical Equation Presented) Intramolecular assistance: Carbon-bound trimethylsilyl groups are activated intramolecularly by a carbonyl group and can participate in Heck reactions under oxidative conditions. Good stereoselectivities are obtained for a range of di-and trisubstituted alkenes (see example).
