Synthesis of functionalized benzimidazoles via oxidative tandem quartic C-H aminations and cleavage of C-N and C-C bonds.

Via aerobic copper-catalyzed tandem quartic C-H aminations, we herein present an unprecedented approach for the synthesis of functionalized benzimidazoles from aniline derivatives and 2-substituted cyclic amines. The cyclic amines act as the CN building blocks and are involved in the annulation reaction by cleavage of inert α-C-N and ß-C-C bonds. The synthetic protocol features high selectivity, no need for specific aminating agents, mild conditions, and the use of a naturally abundant [Cu]/O2 catalyst system.

Selective construction of fused heterocycles by an iridium-catalyzed reductive three-component annulation reaction.

Catalytic conversion of ubiquitously distributed but less reactive N-heteroarenes into functional products remains to date a challenge. Here, through an initial pretreatment of N-heteroarenes with alkyl bromide, we describe a syn-selective construction of functional fused heterocycles via iridium catalyzed reductive annulation of N-heteroarenium salts with formaldehyde and cyclic 1,3-diketones or 4-hydroxycoumarins, proceeding with broad substrate scope, good functional group compatibility, readily available feedstocks, and high step and atom efficiency.

Straightforward access to novel indolo[2,3-b]indoles via aerobic copper-catalyzed [3+2] annulation of diarylamines and indoles.

Herein, we report an unprecedented aerobic copper-catalyzed [3+2] annulation reaction of diarylamines with indoles, which allows direct access to novel 2-diarylaminoindolo[2,3-b]indoles, a class of potential photoelectric device molecules. The developed transformation proceeds with broad substrate scope, good functional group tolerance, high chemo-selectivity, and no need for pre-preparation of specific agents, which offers a practical route for diverse and atom-economic synthesis of the desired products that are difficult to prepare with the conventional approaches.

Direct Access to Functionalized Indoles via Single Electron Oxidation Induced Coupling of Diarylamines with 1,3-Dicarbonyl Compounds.

Under aerobic copper catalysis, an unprecedented direct synthesis of functionalized indoles via single electron oxidation induced coupling of diarylamines with 1,3-dicarbonyl compounds is presented. The protocol proceeds with good functional group and substrate compatibility, the use of readily available feedstocks and naturally abundant catalyst system, high step and atom efficiency, as well as selectivity, which offers a platform for accessing a new class of indoles with the potential for the discovery of functional molecules.

Synthesis of Multisubstituted Benzimidazolones via Copper-Catalyzed Oxidative Tandem C-H Aminations and Alkyl Deconstructive Carbofunctionalization.

Benzimidazolone constitutes the core structure of numerous pharmaceuticals, agrochemicals, inhibitors, pigments, herbicides, and fine chemicals. Amination of hydrocarbons is an attractive tool for the creation of nitrogen-containing products. However, the multiple steps, harsh conditions, and low atom efficiencies often present in these reactions remain challenging. We present a multicomponent synthesis of functional benzimidazolones from arylamines, dialkylamines, and alcohols, acting via the sequence of copper-catalyzed oxidative tandem C-H aminations and alkyl deconstructive carbofunctionalization. The catalytic transformation forms multiple bonds in one single operation, uses readily available feedstocks and a naturally abundant Cu/O2 catalyst system, has broad substrate scope, avoids pre-installation of aminating agents and directing groups, and provides high chemo- and regioselectivity, resulting in direct functionalization of inert C-H and C-C bonds via single-electron oxidation-induced activation mode. This platform can be expected to provide structurally diverse products with interesting biological, chemical, and physical properties.