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/10.1007/5931Keywords:
nitroalkanes, 1, 3, 4-oxadiazoles, semicarbazides, 4-thiadiazoles, thiosemicarbazides, Brønsted acid catalysis, cascade reaction, nucleophilic cycloadition.Abstract
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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Published
2020-09-17
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Original Papers