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The diversity-oriented synthesis of 1,2,4-triazols, 1,3,4-thiadiazols, and 1,3,4-selenadiazoles from N-tosylhydrazones was developed, and the reactions were general for a wide range of substrates, in which NH2CN, KOCN, KSCN, and KSeCN were used as odorless sources. Two different pathways were proposed, and N-tosylhydrazonoyl chlorides were formed in situin the presence of NCS.

A facile method for the preparation of 4,5-diaminopyrazoles from N-tosylhydrazones and isocyanides was developed. The reaction was general for a wide range of substrates, and it demonstrated excellent tolerance to a variety of substituents. More importantly, the protective groups of aminos could be selectively removed by controlling the amount of acid. A novel acid-promoted [3 + 1 + 1] cyclization mechanism was proposed.