White-clark catalyst

The Uses of White-clark catalyst

This catalyst is useful for late-stage functionalization of complex compounds through C-H amination. This catalyst is highly reactive and selective for amination at benzylic positions. The benzylic amination is highly selective over tertiary amination. In substrates with multiple benzylic sites, the preference is for amination at the least sterically encumbered and most electron rich site, irrespective of bond dissociation energy (BDE). Substrates containing basic nitrogen (tertiary amines, pyridine, benzimidazole) can be effectively protected for the first time using this catalyst with a Br?nsted (HBF₄) or Lewis acid (BF₃), to give remotely aminated products. Late-stage amination has been demonstrated on a series of drugs and drug-like molecules, including citalopram, analogs of estrone and dextromethorphan, and biflavanoids, many of which cannot be accessed by other amination methods due to the presence of basic nitrogens.