Recent advances in dearomatization of heteroaromatic compounds

Abstract

Dearomatization reactions provide the most efficient method for the synthesis of spiro- or fused-ring systems from readily available compounds. This review summarizes the recent developments in dearomatization reactions of indoles, pyridines, quinolines, isoquinolines, and some other heteroaromatic compounds. The applications of these methods in total synthesis of natural products are also briefly introduced.

Controlling Stereoselectivity in Tribromide Mediated Oxidative Dearomatisations – Synthesis of Selective Spirofurano‐naphthalones

“…Oxidative dearomatisation of easily available phenols and naphthols have been a lucrative ladder of exploring molecular complexity as they furnish cyclo‐hexadieneones which can easily be functionalised with appropriate nucleophiles to access many natural products of biological relevance (Figure ) Dearomative spiro‐oxacyclisation of arenols is a facile route towards generation of the spiro‐furans since many natural products like Theaspirone, Spiroliganone B and Gimnastatin I contain a spiro‐furan core and exhibit a wide range of bioactivity. Thus, the emphasized biological activity and notable stereochemistry related to spiro‐furans has delivered an important synthetic status to them .…”

New opportunities in the stereoselective dearomatization of indoles

“…Among many catalytic site-controlled stereodefined dearomatizations of indoles [5][6][7][8][9], a most diffuse approach involves the condensation of electron-rich arenes with electrophilic partners properly adapted in a side-chain of the heteroarenes (intramolecular route). Alternatively, intermolecular methodologies have been documented.…”

Palladium(II)‐Catalyzed C3‐Selective Friedel–Crafts Reaction of Indoles with Aziridines

“…Whilst α‐substituted tryptamine derivatives have been shown to have important biological activities, β‐branched systems, which do not occur naturally, have yet to be extensively explored. Tryptamines are also able to undergo direct transformation into pyrroloindolines– or tetrahydro‐β‐carbolines, as well as other polycyclic nitrogen‐containing heterocycles; therefore, β‐branched systems are also potential precursors of C3‐functionalized analogues of these skeletons.…”