Blue light enabled access to novel (hetero)aromatic bridged pyrrolidine alcohols

Abstract

In this work we describe a practical, rapid and robust synthetic route to novel hetero(aromatic) bridged pyrrolidine esters and alcohols. These complex 1-hetero(aryl)-2-azabicyclo[2.1.1]hexanes represent sp3-rich, attractive building blocks for drug discovery. Our methodology utilises widely available and diverse β-keto esters as starting materials. Avoiding UV irradiation, we used a classic iridium complex and mild blue light conditions to facilitate a key triplet state intramolecular [2 + 2] photocycloaddition.