Synthesis of aromatic heterocycles

The Synthesis of Important Pharmaceutical Building Blocks by Palladium‐Catalyzed Coupling Reaction: Access to Various Arylhydrazines

“…The arylhydrazone was obtained as a pale yellow solid (93%). 1 H and 13 C NMR are in accordance with the literature data. [24] N-p-Trifluoromethylphenyl Benzophenone Hydrazone…”

“…1 H and 13 C NMR spectra were determined on a 200 MHz spectrometer. Melting points were determined on a Büchi B-545 capillary melting point apparatus and are uncorrected.. Each compound prepared herein was characterized by GC, GC-MS and 1 H NMR spectroscopy.…”

“…[1] Thus, they are important to a diverse array of fields, such as agrochemicals, pharmaceuticals or photography.…”

Ab initio study of the mechanisms of intermolecular and intramolecular [4?+?2] cycloaddition reactions of conjugated enynes

“…Various substituted enynes were shown to undergo intramolecular cycloaddition reactions providing a new pathway to bicyclic products. [1][2][3][4] The proposed mechanism of the reaction is interesting. The six-membered allene (1,2,4-cyclohexatriene and its derivatives) were suggested as reaction intermediates (Scheme 1).…”

A novel and simple route for the synthesis of 3,4-disubstituted pyrroles

“…The prominent examples are ketorolac, tolmetin and indomethacin [1]. In view of the importance of these compounds substantial attention has been paid to their synthesis, which proceeds mainly via cycloaddition or cycloisomerization of acyclic precursors [2][3][4][5]. Besides, the conjugate addition of nucleophiles to α,β-unsaturated compounds is one of the most powerful bond forming strategies and has been widely utilized in the field of heterocyclic chemistry.…”