New tricks with aryl Grignards

Abstract

A time-honored laboratory exercise for students of organic chemistry is to make a Grignard reagent from magnesium metal turnings and an organohalide so that they can then use the resulting nucleophile to forge a new C–C bond. Chemists led by Rice University’s Laszlo Kurti and Brigham Young University’s Daniel H. Ess now report a way to use stalwart aryl Grignard reagents to fashion C–N and C–O bonds. The chemists found that when they reacted aryl Grignard reagents with a bench-stable, bulky N-H oxaziridine, the nucleophiles attacked the compound’s nitrogen group to generate anilines. Blocking the oxaziridine’s nitrogen with a benzyl group prompted the Grignard to attack the compound’s oxygen atom instead, generating a phenol compound (Nat. Chem. 2016, DOI: 10.1038/nchem.2672). “Our method is really plain and simple,” Kurti says. “You take either of these oxaziridine reagents and now you have the freedom to take the same aryl Grignard and make