Thiol-promoted intermolecular cyclization to synthesize 1,2,4-oxadiazoles including tioxazafen under transition metal-free conditions

Abstract

A simple and efficient one-pot intermolecular annulation reaction for the synthesis of 1,2,4-oxadiazoles from amidoximes and benzyl thiols has been developed, in which benzyl thiols act as not only reactants...

TFA-Mediated Synthesis of 1,2,4-Oxadiazoles from Carbamates and Nitriles

“…Among them, the most widely applied method is the [4+1] assembly reaction of amidoximes. Over the past several decades, carboxylic derivatives, dithioesters, and benzyl thiols have been utilized in the synthesis of 1,2,4-oxadiazoles (Scheme a). Another common approach involves the 1,3-dipolar cycloaddition of nitrile oxides to nitriles or azetine derivatives .…”