346720-06-7Relevant articles and documents
Novel and efficient heterogeneous polymer supported copper catalyst for synthesis of 2-substituted Benzoxazoles from 2-Haloanilides
Saranya, Thachora Venu,Sruthi, Pambingal Rajan,Raj, Veena,Anas, Saithalavi
supporting information, (2021/02/27)
A novel polymer supported copper complex is prepared by the immobilization of copper iodide on chemically modified polyacrylonitrile and its application in heterogeneous catalysis is described. The catalyst was prepared by easy method via synthetic modification of Polyacrylonitrile (PAN) using ethylene diamine followed by the complexation with CuI. After characterization, this complex was explored as a green and efficient heterogeneous catalyst for the synthesis of 2-benzoxazoles from 2-haloanilides. The reaction was performed without adding additional ligand and the catalyst shows activity over a broad range of substrates with quantitative product yields. The catalyst was easily recovered by simple filtration and reused successfully for further cycle.
Photocatalyst- And Transition-Metal-Free Visible-Light-Promoted Intramolecular C(sp2)-S Formation
Wang, Hao,Wu, Qi,Zhang, Jian-Dong,Li, Hai-Yan,Li, Hong-Xi
supporting information, p. 2078 - 2083 (2021/04/05)
A photocatalyst- and transition-metal-free visible-light-induced cyclization of ortho-halothiobenzanilides has been developed. Upon irradiation with visible light, substrates undergo dehalogenative cyclization to 2-aryl benzothiazoles with high efficiency and selectivity. This photocyclization exhibits a high tolerance to various functional groups, is applicable for the synthesis of 2-alkyl benzothiazoles, and is easy to set up for gram-scale reaction.
Palladium-Catalyzed, ortho-Selective C-H Halogenation of Benzyl Nitriles, Aryl Weinreb Amides, and Anilides
Das, Riki,Kapur, Manmohan
, p. 1114 - 1126 (2018/06/18)
A palladium-catalyzed, ortho-selective C-H halogenation methodology is reported herein. The highlight of the work is the highly selective C(sp2)-H functionalization of benzyl nitriles in the presence of activated C(sp3)-H bond, which results in good yields of the halogenated products with excellent regioselectivity. Along with benzyl nitriles, aryl Weinreb amides and anilides have been evaluated for the transformation using aprotic conditions. Mechanistic studies yield interesting aspects with respect to the pathway of the reaction and the directing group abilities.
A comparative study of the catalytic activity of Co- and CoFe2O4-NPs in C-N and C-O bond formation: synthesis of benzimidazoles and benzoxazoles from o-haloanilides
Hajipour, Abdol R.,Khorsandi, Zahra
, p. 10474 - 10481 (2016/12/07)
Nanoparticles of cobalt ferrite (CoFe2O4-NPs) and pure cobalt (Co-NPs) were synthesized, and after characterization, their catalytic activities for dehalogenative intramolecular C-O and C-N bond formation reactions were investigated and compared. These inexpensive and efficient catalysts enabled creation of new methods for the synthesis of benzimidazoles and benzoxazoles in green media, with ligand-free and mild reaction conditions. All the reactions resulted in moderate to excellent yields under the optimized reaction conditions; however, the reactions using Co-NPs as the catalyst were completed in relatively shorter reaction times. Furthermore, analysis showed that the reusability of the two catalytic systems is approximately comparable.
New palladium-catalyzed domino reaction with intramolecular ring closure of an N-(2-chloro-3-heteroaryl)arylamide: First synthesis of oxazolo[4,5-b] pyrazines
Demmer, Charles S.,Hansen, Jacob C.,Kehler, Jan,Bunch, Lennart
, p. 1047 - 1055 (2014/04/03)
The synthesis of novel planar heterocycles is at the heart of basic research as such scaffolds constitute key building blocks in important diverse areas of research: drug discovery, material sciences, and pesticides. The well-known benzoxazole is often contained in drug candidates but tweaking its lipophilicity and target interaction points are often desired. In this respect, the oxazolo[4,5-b]pyrazine is an attractive heterocyclic scaffold as it possesses increased water solubility as well as two additional hydrogen bonding acceptors. We here report a new Pd(II)-catalyzed domino reaction comprising the first Pd(II)-assisted intramolecular cyclization of an N-(2-chloro-3-heteroaryl) arylamide and validate its value by application to the first synthesis of 2-substituted oxazolo[4,5-b]pyrazines. We demonstrate that a bidentate phosphorus ligand as well as the presence of an aromatic nitrogen atom is required for the domino reaction to proceed. The robustness of the methodology is confirmed by the synthesis of 23 2-substituted oxazolo[4,5-b]pyrazine analogues in good-to-high yields and containing both electron-withdrawing as well as electron-donating substituents on the reacting arylamide.
Pd(OAc)2-catalyzed carbonylative coupling of aryl iodide with ortho-haloamines in water
Tambade, Pawan J.,Patil, Yogesh P.,Qureshi, Ziyauddin S.,Dhake, Kishor P.,Bhanage, Bhalchandra M.
supporting information; experimental part, p. 176 - 185 (2011/10/31)
The carbonylative cross coupling of aryl iodide with ortho-haloaniline to ortho-haloanilide using phosphine-free Pd(OAc)2 catalyst in water as a reaction medium has been studied. The present protocol facilitated the reaction of o-haloanilines with a wide variety of hindered and functionalized aryl iodides, affording good yields of the desired products. The protocol was also extended for the synthesis of benzoxazoles through cyclization of ortho-haloanilide using Cu(acac)2 catalyst. Taylor & Francis Group, LLC.
Structural development studies of anti-hepatitis C virus agents with a phenanthridinone skeleton
Nakamura, Masahiko,Aoyama, Atsushi,Salim, Mohammed T.A.,Okamoto, Mika,Baba, Masanori,Miyachi, Hiroyuki,Hashimoto, Yuichi,Aoyama, Hiroshi
scheme or table, p. 2402 - 2411 (2010/06/20)
A phenanthridinone skeleton was derived from our previous researches on thalidomide and retinoids as a multi-template for generation of anti-viral lead compounds. Structural development studies focusing on anti-hepatitis C virus activity afforded 5-butyl-2-(1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)phenanthridin-6(5H)-one (10) and 5-butylbenzo[b]phenanthridin-6(5H)-one (39), which showed EC50 values of approximately 3.7 and 3.2 μM, respectively.
