The development of multicomponent reactions for indole synthesis is demanding and has hardly been explored. The present study describes the development of a novel multicomponent, cascade approach for indole synthesis. Various substituted indole derivatives were obtained from simple reagents, such as unfunctionalized alkenes, diazonium salts, and sodium triflinate, by using an established straig...

Cellulose sulfuric acid is an efficient metal-free catalyst for the synthesis of 1,3,5-trisubstituted pyrazoles via the condensation of 1,3-diketones and hydrazines. The reaction was carried out in Solvent-free condition at room temperature and the products were isolated in good to excellent yields. Mild reaction conditions, as well as ease of operation and workup are some advantages of the pro...

A variety of heteroaromatic compounds, such as substituted pyridines, pyrazoles, indoles, 2-substituted imidazoles, 2-substituted imidazoles, 2-arylbenzazoles and pyrimidin-2(1H)-ones are synthesized by oxidative aromatization using the activated carbon and molecular oxygen system. Mechanistic study focused on the role of activated carbon in the synthesis of 2-arylbenzazoles is also discussed. ...

An efficient synthesis of pyrazoles from tosylhydrazones and nitroalkenes was developed. In comparison with the previously reported 1,3-dipolar cycloaddition reaction of diazo compounds with electron-deficient alkenes or alkynes, this methodology proceeded with a sequential Baylis-Hillman/intramolecular cyclization mechanism and a variety of reversed regioselectivity products were prepared in g...

The synthesis under MW irradiation without solvent of 19 pyrazoles, of which only 8 were known, is described. They bear C-methyl groups and trityl, diphenylmethyl and benzyl groups at positions 1 and 4 of the pyrazole ring. In the reaction between pyrazole and trityl bromide an unexpected reaction occurred and 4-(9-phenyl-9H-fluoren-9-yl)-1Hpyrazole (7) was isolated.

A straightforward methodology for the regioselective synthesis of pyrazoles has been developed by a domino sequence based on photoclick cycloaddition followed photocatalyzed oxidative deformylation reaction. Distinguishing features this protocol include an unprecedented photoredox-catalyzed Norrish type fragmentation under green-light irradiation and use α,β-unsaturated aldehydes as synthetic e...