Ring Distortion Diversity‐Oriented Approach to Fully Substituted Furoxans and Isoxazoles

A regioselective method for an assembly of pharmacologically relevant fully substituted furoxans and isoxazoles using the ring distortion diversity‐oriented approach through the one‐pot ring cleavage/nucleophilic addition/oxidation cascade of monosubstituted furoxans was developed. The described synthetic strategy is highly regioselective and provides single furoxan regioisomers upon utilization of N‐ or S‐nucleophiles. Utilization of the cyanide‐anion as a nucleophile in the same reaction cascade afforded a series of rather rare fully substituted isoxazoles incorporating vicinal nitro and amino functionalities. In addition, synthesized disubstituted furoxans revealed an ability to release NO indicating their strong potential as pharmacologically oriented drug candidates for various biomedical applications. Furoxan as precursor: An operationally simple assembly of pharmacologically oriented fully substituted furoxans and isoxazoles was achieved. The presented protocol is based on a one‐pot ring cleavage/nucleophilic addition/oxidation cascade of readily available monosubstituted furoxans. Synthesized disubstituted furoxans revealed an ability to release NO which indicate their strong potential as drug candidates for various biomedical applications.