A Diversified Assembly of 1,2,4-Oxadiazol-3-amines: Metallic Thiophile Catalyzed Chemoselective One-Pot Reaction of Aryl Isothiocyanates, Amidines/Guanidines, and Hydroxylamine
摘要:
An efficient one-pot synthesis of 1,2,4-oxadiazol-3-amines from simple starting materials, isothiocyanates, amidines/guanidines, and hydroxylamine, is described. The reaction is facilitated by metallic-thiophile-assisted desulfurization of in situ formed amidino- or guanidinothiourea to give chemoselectively N-hydroxyguanidine intermediates that give exclusively various 1,2,4-oxadiazol-3-amines in good to excellent yields. The reaction mechanistic pathway may proceed through an intramolecular 5-exotrig cyclization.
(3+2) Annulation of Amidinothioureas with Binucleophile: Synthesis and Antimicrobial Activity of 3-Phenylamino-5-aryl/alkyl-1,2,4-oxadiazole Derivatives
作者:Swapnil G. Yerande、Amruta B. Ghaisas、Kiran M. Newase、Wei Wang、Kan Wang、Alexander Dömling
DOI:10.1002/jhet.1873
日期:2014.11
efficient method for preparation of 3‐phenylamino‐5‐aryl/alkyl‐1,2,4‐oxadiazole by (3+2) annulation of amidinothioureas with binucleophilic hydroxylamine hydrochloride in the presence of mercury (II) chloride. Desired 3‐phenylamino‐5‐aryl/alkyl‐1,2,4‐oxadiazole was prepared in good to moderate yields. On the basis of the literature precedence, the mechanism for the formation of 3‐phenylamino‐5‐aryl/alkyl‐1