Azo-Povarov Cycloaddition of N-Carbonyl Aryldiazenes with cis,trans-Cycloocta-1,5-diene as a Fluorogenic Click Reaction for the Synthesis of Cinnoline Derivatives.

-cycloocta-1,5-diene. This uncatalyzed [4 + 2] cycloaddition reaction enables the synthesis of a broad series of cinnoline derivatives at room temperature, in short reaction times and excellent yields (up to 98%). The functionality of the reaction has been also evidenced through the report of a high-yielding gram-scale synthesis as well as diverse transformations of the final cinnoline substrates. Furthermore, an activatable fluorogenic version of the reaction has been developed using quenched azo-fluorophores as starting materials.