Versatile approach to heteroarylfuroxan derivatives from oximinofuroxans via a one-pot, nitration/thermolysis/[3+2]-cycloaddition cascade

摘要

A simple, general, and regioselective method has been developed for the synthesis of a series of heteroarylfuroxans, including isoxazolyl-, isoxazolinyl- and (1,2,4-oxadiazolyl)furoxans. The described method is based on a cascade of one-pot processes, including the nitration of furoxancarbaldehyde oximes, thermolysis of the formed nitrolic acids to generate furoxancarbonitrile oxides, and [3+2]-cycloaddition with an appropriate dipolarophile – alkynes, olefins, or activated nitriles.