15728-51-5Relevant academic research and scientific papers
An Unexpected Formation of 2-Arylbenzimidazoles from α,α-Diiodo-α’-acetoxyketones and o-Phenylenediamines
Sadhukhan, Santu,Mondal, Swagata,Baire, Beeraiah
, (2022/03/01)
An unusual reactivity of the α,α-diiodo-α’-acetoxyketones with o-phenylenediamines is reported through the formation of 2-arylbenzimidazoles. A systematic study through a series of fruitful control experiments and isolation of key intermediates unravelled the unprecedented domino mechanism. This process involves a stepwise two-carbon fragmentation pathway through domino and sequential amidation–aziridination–decarbonylation–I2-mediated aminative cyclization–oxidation reactions. This strategy employs no additives like oxidant, metal catalyst, bases, and represents yet another novel reactivity profile of the building blocks α,α-diiodo-α’-acetoxyketones.
An Intramolecular C(sp2)–H Amidation Using N-Iodosuccinimide
Alam, Md Toufique,Maiti, Saikat,Mal, Prasenjit
, p. 4178 - 4186 (2018/08/21)
An N-iodosuccinimide (NIS) mediated intramolecular dehydrogenative C(sp2)–H amidation is reported for easy and convenient access to 1,2-disubstituted benzimidazoles. The nonprefunctionalized C(sp2)–H and N(sp3)–H bonds wer
Preparation method of 1,2-substituted benzimidazole derivative
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Paragraph 0020; 0021; 0022; 0023, (2017/09/01)
The invention discloses a preparation method of a 1,2-substituted benzimidazole derivative. The preparation method comprises the following steps: uniformly mixing an N-phenyl amidine derivative, a nitrine derivative, an acid compound, a catalyst, a metal salt and an organic solvent; and performing a reaction for 10-13h at 78-82 DEG C in an air atmosphere to obtain the 1,2-substituted benzimidazole derivative. The method disclosed by the invention can be used for synthesizing a compound with a benzimidazole derivative framework, which cannot be synthesized by other methods. The used raw materials are easily available, and the preparation method is high in yield, mild in reaction condition, wide in primer range, small in catalyst dosage, strong in reaction specificity and simple and green in post-treatment, and the utilization ratio of atoms reaches up to 90% and above.
Iridium(III)-Catalyzed One-Pot Access to 1,2-Disubstituted Benzimidazoles Starting from Imidamides and Sulfonyl Azides
Xu, Linhua,Wang, Lianhui,Feng, Yadong,Li, Yudong,Yang, Lei,Cui, Xiuling
supporting information, p. 4343 - 4346 (2017/08/23)
A novel Ir-catalyzed annulation of imidamides with sulfonyl azides has been developed. 1,2-Disubstituted benzimidazoles could be easily obtained in up to 99% yield for more than 40 examples. The products further streamline the synthesis of molecules that are important building blocks for organic synthesis and drug discovery. This strategy features high regioselectivity, efficiency, good tolerance of functional groups, and mild reaction conditions.
I2-Mediated Intramolecular C-H Amidation for the Synthesis of N-Substituted Benzimidazoles
Hu, Zhiyuan,Zhao, Ting,Wang, Manman,Wu, Jie,Yu, Wenquan,Chang, Junbiao
, p. 3152 - 3158 (2017/03/23)
A practical intramolecular C-H amidation methodology has been developed using molecular iodine under basic conditions. The required imine substrates were readily obtained by condensation of simple o-phenylenediamine derivatives and aldehydes. The transition-metal-free cyclization reaction described here works well with crude imines and allows for the sequential synthesis of N-protected benzimidazoles without purification of the less stable condensation intermediates. This operationally simple synthetic approach is broadly applicable to a variety of aromatic, aliphatic, and cinnamic aldehydes to produce diverse 1,2-disubstituted benzimidazole derivatives in an efficient and scalable fashion.
Hypervalent iodine-mediated synthesis of benzoxazoles and benzimidazoles via an oxidative rearrangement
Zhang, Xiaohui,Huang, Ruofeng,Marrot, Jér?me,Coeffard, Vincent,Xiong, Yan
, p. 700 - 708 (2015/02/02)
A Beckmann-type rearrangement of o-hydroxy and o-aminoaryl N-H ketimines has been developed to prepare benzoxazoles and N-Ts benzimidazoles, respectively. The ketimine derivatives were easily prepared by condensation of ammonia with the corresponding ketones and (diacetoxyiodo)benzene was found to act as an efficient oxidant to trigger the [1,2]-aryl migration towards the formation of the desired heterocycles. Depending on the substitution pattern, the results revealed another mechanistic pathway through which benzisoxazoles or 1H-indazoles could be formed. The Beckmann-type rearrangement strategy was applied to the synthesis of benzimidazole-containing biorelevant targets such as chlormidazole and clemizole.
Palladium-catalyzed intramolecular sulfonamidation/oxidation of imines: Access to multifunctional benzimidazoles
Fu, Shaomin,Jiang, Huanfeng,Deng, Yuanfu,Zeng, Wei
experimental part, p. 2795 - 2804 (2011/12/01)
O-Sulfonamidophenylimines undergo intramolecular sulfonamidation/oxidation to produce 1,2-disubstituted benzimidazoles upon treatment with palladium(II) chloride/(diacetoxyiodo)benzene and potassium carbonate at room temperature. The substituent scope at
