Aromatic hydrocarbons are some of the most elementary feedstock chemicals, produced annually on a million metric ton scale, and are used in the production of polymers, paints, agrochemicals and pharmaceuticals. Dearomatization reactions convert simple, readily available arenes into more complex molecules with broader potential utility, however, despite substantial progress and achievements in this field, there are relatively few methods for the dearomatization of simple arenes that also selectively introduce functionality. Here we describe a new dearomatization process that involves visible-light activation of small heteroatom-containing organic molecules—arenophiles—that results in their para-cycloaddition with a variety of aromatic compounds. The approach uses N–N-arenophiles to enable dearomative dihydroxylation and diaminodihydroxylation of simple arenes. This strategy provides direct and selective access to highly functionalized cyclohexenes and cyclohexadienes and is orthogonal to existing chemical and biological dearomatization processes. Finally, we demonstrate the synthetic utility of this strategy with the concise synthesis of several biologically active compounds and natural products.

Vinyl azides are highly versatile synthons that provide access to numerous N-heterocycles and other functional groups. α-Substituted vinyl azides (azido vinylidenes) are a special class that display unique reactivity, able to react not only as azides, but also as radical acceptors, enamine-type nucleophiles, and even electrophiles, thus delivering a wide range of nitrogen-containing compounds and their derivatives. An impressive variety of intermediates - such as iminodiazonium ions, nitrilium ions, iminyl radicals, and metal enaminyl radicals - can be generated from vinyl azides and exploited in cycloadditions, C-H functionalizations, hydrolysis processes, and cascade reactions under transition metal/photoredox catalysis. In addition to presenting synthetic protocols to access vinyl azides, this Review offers a comprehensive coverage of the development of their multifaceted reactivity, and highlights their potential as versatile precursors for synthetic applications.

A diverse collection of copper-catalyzed intermolecular aminative difunctionalizations of unactivated alkenes with N-halodialkylamines as the terminal dialkylamino source is reported. A bidentate auxiliary tethered on the alkene substrates is crucial, which can promote the migratory insertion of nonactivated alkenes into the aminyl radical–metal complex and stabilize the resultant high-valent copper intermediate to allow for further transformations. By employing this strategy, the intermolecular aminohalogenation reactions and a three-component aminoazidation reaction of unactivated alkenes with dialkylamino source were successively achieved in a remarkable regio- and stereoselective manner. These reactions were performed under neutral conditions and maintained excellent functional group tolerance toward a wide range of N-halodialkylamines and unactivated alkenes. Further mechanistic studies and DFT calculations supported a concerted migratory insertion of the C–C double bond into the aminyl radical–metal complex to form a Cu­(III) intermediate.

A new type of intermolecular alkylative olefination of unactivated olefins and alkyl halides has been realized for the first time. This copper-promoted Heck-type reaction employs a directing-group strategy to efficiently produce the coupled alkyl olefin products with excellent regio- and stereoselectivity. A broad substrate scope including 1°, 2°, and 3° alkyl bromides and various nonactivated alkenes could be well tolerated. DFT calculations disclosed a dimethyl sulfoxide assisted concerted H–Br elimination process of a conformationally strained Cu­(III) cyclic transition state.