809231-03-6Relevant academic research and scientific papers
One-pot strategy of copper-catalyzed synthesis of 1,2-disubstituted benzimidazoles
Xie, Caixia,Han, Xushuang,Gong, Jian,Li, Danyang,Ma, Chen
supporting information, p. 5811 - 5819 (2017/07/22)
A simple, one-pot and copper-catalyzed coupling reaction for the construction of 1,2-disubstituted benzimidazole derivatives is described. A low-cost copper salt and a weak base K3PO4 were utilized in this reaction. A variety of 1,2-disubstituted benzimidazoles were obtained in moderate to excellent yields.
Sulfate Radical Anion (SO4?-) Mediated C(sp3)-H Nitrogenation/Oxygenation in N-Aryl Benzylic Amines Expanded the Scope for the Synthesis of Benzamidine/Oxazine Heterocycles
Laha, Joydev K.,Tummalapalli, K. S. Satyanarayana,Nair, Akshay,Patel, Nidhi
, p. 11351 - 11359 (2015/12/01)
A transition-metal-free, K2S2O8-mediated intramolecular oxidative nitrogenation/oxygenation of C(sp3)-H in N-aryl benzylic amines followed by oxidation at the benzylic center has been developed for the synthesis of benzamidine/benzoxazine heterocycles, providing an expedient access to quinazolin-4(3H)-ones, N-aryl-2-arylbenzimidazoles, and 4H-3,1-benzoxazin-4-ones. A considerable amount of work dealing with the mechanistic study to understand the crucial intramolecular cyclization step largely favors an iminium ion as the key intermediate.
Rhodium-catalyzed domino conjugate addition-cyclization reactions for the synthesis of a variety of N- and O-heterocycles: Arylboroxines as effective carbon nucleophiles
Park, Ja Ock,Youn, So Won
supporting information; experimental part, p. 2258 - 2261 (2010/07/17)
Facile and efficient Rh(I)-catalyzed domino conjugate addition-cyclization reactions of olefins bearing two electrophilic sites and a pendant nucleophile with organoboroxines have been developed to afford a variety of N- and O-heterocycles, such as 3,4-dihydroquinolin-2(1H)-ones, 3,4-dihydrocoumarins, and pyrrolidin-2-ones, which constitute important motifs in biologically active natural and synthetic organic compounds.
Copper-catalyzed intramolecular N-arylation of ureas in water: a novel entry to benzoimidazolones
Barbero, Nekane,Carril, Mónica,SanMartin, Raul,Domínguez, Esther
, p. 7283 - 7288 (2008/09/21)
The copper-catalyzed intramolecular N-arylation of 2-bromoarylureas performed in water leading to the benzo[d]imidazolone framework is reported. The scope of the methodology presented herein proved to?be broad and afforded a significant number of benzoimidazolones in good to excellent yields. The reported protocol is based on the use of CuI and TMEDA acting both as the ligand and as the base in a water solution, which allows for the easy separation of the catalyst containing aqueous phase from the products by simple extraction. Additionally, the N- versus O-arylation competitive processes are also discussed.
Indole synthesis by controlled carbolithiation of o-aminostyrenes
Kessler, Albane,Coleman, Claire M.,Charoenying, Patchanee,O'Shea, Donal F.
, p. 7836 - 7846 (2007/10/03)
An effective synthesis of the functionalized indole ring system has been developed from substituted o-aminostyrene starting material. Our methodology involves a novel cascade reaction sequence of alkyllithium addition to the styrene double bond and subsequent trapping of the intermediate organolithium with a suitable electrophile, followed by an in situ ring closure and dehydration to generate the indole ring. This new reaction sequence allows for the introduction of molecular diversity at all positions on the indole scaffold. The procedure was shown to be successful with a range of both C and N substituents on the o-aminostyrenes. The reaction sequence was tolerant to the reactivity range of alkyllithiums such as tert-, sec-, and n-butyllithium. The electrophiles used were DMF, which generated indole products with C-2 unsubstituted, and nitriles, which incorporated the nitrile substituent at C-2. The o-aminostyrene starting materials were generated by a Pd-catalyzed cross-coupling reaction of a vinyl boronic acid equivalent with the readily available substituted o-bromoanilines.
