Intramolecular [2+2] Photocycloaddition of Substituted Isoquinolones: Enantioselectivity and Kinetic Resolution Induced by a Chiral Template

From simple to complex: Starting from easily accessible isoquinolones 1 (X=Br, OH), complex cyclobutane photoproducts such as compound 2 can be obtained with high enantioselectivity (88–96 % ee) through the use of a chiral template. Compound 3, which was isolated in 53 % ee starting from a racemic substrate, is the product of a unique, unprecedented kinetic resolution process.