Heterocycle missing link unveiled

Abstract

Chemists over the years have combined boron, carbon, nitrogen, and oxygen in various ways to create a variety of six-membered heterocyclic ring systems. One of the reasons they make these rings is to expand the array of available polycyclic aromatic materials used for making optoelectronic devices and used as organocatalysts. In particular, researchers have been looking at graphite-type materials based on six-membered ring core structures containing electron-deficient boron atoms. But incorporating both nitrogen and oxygen along with boron has remained elusive. A research team at Japan’s Institute of Microbial Chemistry has now designed and synthesized oxaazaborinanes—molecules that contain a B3NO2 ring—that are a cross between previously known borazines (B3N3) and boroxines (B3O3). The new ring had been a missing link in the collection of six-membered ring compounds containing B, C, N, and O (Nat. Chem. 2017, DOI: 10.1038/nchem.2708). The team led by Masakatsu Shibasaki and Naoya Kumagai prepared a set