Recent Developments in Arene Photocycloadditions

The photocycloaddition of alkenes with aromatic systems may proceed through three reaction modes, affording different types of products: ortho, meta, and para. These reactions generate a considerable increase in complexity, and yield products arduously attainable by classical synthetic steps. Whereas the meta-photocycloaddition has gained a lot of attention in the last decades because of its applicability in the total synthesis of numerous natural products, the ortho- and para-cycloadditions still have a great potential for further development. In this highlight, we review the latest advances in the field of photocycloaddition of alkenes to aromatic systems.