Dearomatisation - An Unsolved Riddle

Abstract

Dearomatization is a versatile synthetic tool for transformation of a simple planar molecule to a more functionalised diverse non-planar molecular skeleton allowing a fast access to synthetic complexity. Oxidative dearomatisation is a fantastic protocol for developing rapid and controlled generation of complex, readily functionalizable three-dimensional structures from simple planar starting materials is a highly attractive goal, as it allows fast access to diverse molecular architectures. Dearomatization of arenes is a powerful approach that has been proposed as a key component in putative biosynthetic pathways for a range of bioactive natural products, inspiring a range of elegant syntheses. A highly desirable factor in such constructions is the induction of asymmetry into the product, which has generally been achieved by three distinct chemical approaches: diastereoselective dearomatization of a substrate bearing an existing stereocenter. However, generalized, cheap and scalable approaches towards this reaction are scarce and none is catalytic. Cyclohexadieneones and naphthalenones are important structural motifs which serve as effective molecules towards complex natural product synthesis. Notably, the last decade has seen a tremendous urge to develop sustainable versions of this transformation which can be applied to a wider context. Important functionalisation along with conversion of these planar molecules to three dimensional molecules like Aminocyclohexadieneones, azido-napthaleneones and Peroxo-cyclohexadieneones constitute the central core for a vast set of medicinally important molecules and thus create an extreme focus of attention. Certainly, a generalised oxidative strategy which carefully aaccomplishes this “trio” of reactions aminative, azidative and Peroxodative dearomatisations can be a reaction of tremendous synthetic importance. This trio of reactions has been accomplished using Phenyl trimethyl ammonium tribromide(PTAB) as an effective reagent.