Phenylselenenyl sulfate induced cyclization of allylhydrazines. Synthesis of pyrazole derivatives
摘要:
Allylhydrazines react with phenylselenenyl sulfate, produced by diphenyl diselenide and ammonium persulfate in the presence of trifluoromethanesulfonic acid, to afford phenylseleno substituted pyrazolidines. Under the reaction conditions employed, these suffer dehydrogenation and oxidative deselenenylation to eventually give pyrazole derivatives. (C) 1997 Elsevier Science Ltd.
palladium-catalyzed allylation of hydrazines with allylalcohols and aldehydes was developed, enabling the syntheses of a series of allylhydrazones in good to excellent yields with high regioselectivity. Furthermore, the four-component tandem allylation carbonylation of hydrazines with allylalcohols and aldehydes was established using the catalytic system, producing various allyl acylhydrazones. Additionally