Enantioselective Organophotocatalytic α-Functionalization of Aldehydes with -Lactam Radicals: A Viable Strategy for the Telescoped Synthesis of Levetiracetam.

The mild photocatalytic generation of -lactam radicals is explored for the enantioselective α-functionalization of aldehydes in the presence of a chiral imidazolidinone organocatalyst. The reaction provides the desired products in high yields and up to 92% ee using a structurally simple, low-cost, and easy-to-prepare organocatalyst. The methodology was successfully applied to the telescoped synthesis of a pharmacologically relevant compound, ()-levetiracetam, an antiepileptic drug.