Catalyst-free microwave-assisted azo-Povarov reaction of N-carbonyl aryldiazenes with trans-cyclooctene to access ring-fused cinnoline derivatives

Abstract

A previously unprecedented azo-Povarov reaction between N-carbonyl aryldiazenes and trans-cyclooctene derivatives has been developed. The participation of these aryldiazenes in the uncatalyzed [4 + 2] cycloaddition reaction has enabled the construction of a variety of appealing fused cinnoline derivatives, with yields ranging from 34% to 91% across a broad substrate scope. The starting materials are cost-effective and readily accessible, while the reaction conditions and procedures are straightforward, requiring no external catalysts. Moreover, the synthetic significance of this methodology has been demonstrated through a gram-scale azo-Povarov reaction and further derivatizations of the resulting N-containing heterocycles.