Synthesis of 2-Azabicycles via Samarium(II)-Promoted Cyclization of Imides

Cyclization of Imides to 2-Azabicycles via Aminoketyl Radicals by Using Samarium(II) Iodide–Water: Reaction Development, Synthetic Scope, and Mechanistic Studies: S. Shi, R. Lalancette, M. Szostak
Synthesis 2016, 48, DOI: 10.1055/s-0035-1560437

Samarium(II) iodide is an important reagent in the toolbox of organic chemists, particularly for achieving radical cyclizations involving oxygen-containing carbonyl electrophiles, whereas nitrogen-containing acceptors have received much less attention. Recently, Professor Michal Szostak from Rutgers University (Newark, USA) has published the Samarium(II)-promoted cyclization of imides to 2-azabicycles via aminoketyl radicals.

Professor Szostak said: “Samarium diiodide has long been known to generate all sorts of radicals. The concept of using samarium diiodide to create aminoketyl radicals – so far elusive species in organic reactions – could extend the capability of radical chemistry for real-life applications. We are convinced that the high diastereoselectivity and exceptional functional group tolerance of this transformation makes it a very attractive tool for pharmaceutical and complex natural product synthesis. Nitrogen‐containing groups are the key component of many drugs and bioactive natural products. We expect that this work will inspire many more related single-electron-transfer processes using low-valent lanthanide and titanocene reagents.”