Figure 2.

Substrate scope of [3 + 2] and [4 + 2] annulation reactions. Reactions run on 0.5 mmol scale unless otherwise noted. Yields are for isolated material and are the average of two runs. All products generated from achiral starting materials are racemic. ^aGram-scale reaction performed using 0.2 mol % photocatalyst with 24 h. reaction time. ^bReaction performed on 0.1 mmol scale. ^cGram-scale reaction performed using 0.5 mol % photocatalyst. See the Supporting Information for details on relative stoichiometries of reagents.