Arene C–H Amination with <i>N</i>-Heteroarenes by Catalytic DDQ Photocatalysis
Kaii Nakayama, Yohei Okada
Abstract
Arene C–H aminations using catalytic amounts of a 2,3-dichloro-5,6-dicyano- p -benzoquinone (DDQ) photocatalyst are described. Benzene, which has an oxidation potential of 2.48 V (vs SCE), was functionalized by pyrazoles, triazoles, tetrazoles, purines, and tert -butoxycarbonyl amine. Arenes underwent amination via a combination of ultraviolet (UV) light and a DDQ photocatalyst without a typical co-oxidant. Although the mechanism remains an open question, DDQH 2, which is generated from DDQ after oxidation, is reactivated to DDQ under UV light irradiation conditions, possibly with the assistance of adventitious O 2 and/or a solvent as the terminal oxidant(s) in this system.
Topics & Concepts
AminationPhotocatalysisChemistryBenzoquinoneCatalysisBenzeneAmine gas treatingPhotochemistryMedicinal chemistryNuclear chemistryOrganic chemistryRadical Photochemical ReactionsSynthesis and Catalytic ReactionsCatalytic C–H Functionalization Methods