European Journal of Organic Chemistry 2018-02-20

A Bird's Eye View of Atropisomers Featuring a Five‐Membered Ring

Damien Bonne; Jean Rodriguez

Index: 10.1002/ejoc.201800078

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Abstract

Atropisomers are a subclass of restricted rotational conformers, resulting in a stereogenic sigma bond, which can be isolated as separate chemical species. Most of them concern six‐membered ring biaryl or heterobiaryl derivatives. The aim of this microreview is to shed light on a less common class of atropisomers composed of at least one five‐membered hetero‐ or carbocycle, displaying either a stereogenic C‐N, C‐C or even N‐N chemical bond. After a short introduction, their occurrence in Nature and the synthetic efforts, including non‐stereoselective, diastereoselective and an update on very recent enantioselective approaches of such axially chiral molecules, are presented. Finally, a special focus is given to their important utilization as original and efficient ligands for metal complexes.