PREPARATION OF 1,3,4-OXADIAZOLES AND 1,3,4-THIADIAZOLES <i>VIA</i> CHEMOSELECTIVE СYCLOCONDENSATION OF ELECTROPHILICALLY ACTIVATED NITROALKANES TO (THIO)SEMICARBAZIDES OR THIOHYDRAZIDES
DOI:
https://doi.org/10.1007/5931Ключевые слова:
nitroalkanes, 1, 3, 4-oxadiazoles, semicarbazides, 4-thiadiazoles, thiosemicarbazides, Brønsted acid catalysis, cascade reaction, nucleophilic cycloadition.Аннотация
Unusual reaction proceeding via the electrophilic activation of nitroalkanes in the presence of polyphosphoric acid has been discovered. Subsequent nucleophilic attack with semicarbazides or thiosemicarbazides allows to access 2-amino-1,3,4-oxadiazoles and 2-amino-1,3,4-thiadiazoles, respectively.
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Опубликован
2020-09-17
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Оригинальные статьи