Design and synthesis of pyrazolo[3,4-d]pyridazine 5,6-dioxides as novel NO-donors

Regioselective Synthesis of NO-Donor (4-Nitro-1,2,3-triazolyl)furoxans via Eliminative Azide-Olefin Cycloaddition

A facile and efficient method for the regioselective [3 + 2] cycloaddition of 4-azidofuroxans to 1-dimethylamino-2-nitroethylene under p-TSA catalysis affording (4-nitro-1,2,3-triazolyl)furoxans was developed. This transformation is believed to proceed via eliminative azide-olefin cycloaddition resulting in its complete regioselectivity. The developed protocol has a broad substrate scope and enables a straightforward assembly of the 4-nitro-1,2,3-triazole motif. Moreover, synthesized (4-nitro-1,2,3-triazolyl)furoxans were found to be capable of NO release in a broad range of concentrations, thus providing a novel platform for future drug design and related biomedical applications of heterocyclic NO donors.

Synthesis of heterocyclic (triazole, furoxan, furazan) fused pyridazine di-N-oxides via hypervalent iodine oxidation

Use of a mild PIDA oxidation strategy to access heterocyclic (triazole, furoxan, furazan) fused pyridazine di-N-oxides.