A Photoinduced, Benzyne Click Reaction

The [3 + 2] cycloaddition of azides and alkynes has proven invaluable across numerous scientific disciplines for imaging, cross-linking, and site-specific labeling among many other applications. We have developed a photoinitiated, benzyne-based [3 + 2] cycloaddition that is tolerant of a variety of functional groups as well as polar, protic solvents. The reaction is complete on the minute time scale using a single equivalent of partner azide, and the benzyne photo-precursor is stable for months under ambient light at room tempurature. Herein we report the optimization and scope of the photoinitiated reaction as well as characterization of the cycloaddition products.