Copper-Catalyzed Synthesis of Indolyl Benzo[b]carbazoles and Their Photoluminescence Property

Gold-Catalyzed Reactions of Enynals with Alkenes for Synthesis Binaphthyl Derivatives

A PPh3Au[B(C6F5)4]-catalyzed reaction of enynals and alkenes for the construction of binaphthyl derivatives was described. This transformation was achieved through o-Quinodimethane (o-QDM) intermediate's extended conjugated addition process. The reaction has the advantages of wide substrate scopes, mild reaction conditions, high efficiency, and good scalability.

A one-pot telescopic synthesis of benzo[b]carbazoles and exploration of their liquid crystalline properties

We describe a diversity-oriented one-pot telescopic synthesis of various benzo[b]carbazoles with the naphthannulation of indoles as the key step, enabled by an intramolecular furan-olefin Diels-Alder reaction. This strategy is general and efficient across a wide range of substrates. We applied this method to synthesize and characterize the first benzo[b]carbazole-based liquid crystalline materials, where the unique molecular design led to the formation of a rare nematic phase at room temperature.

Iodine-Catalyzed Annulation Reaction of Ortho-Formylarylketones with Indoles: A General Strategy for the Synthesis of Indolylbenzo[b]carbazoles

The iodine-catalyzed cascade reaction of ortho-formylarylketones with indoles for the synthesis of indolylbenzo[b]carbazoles is reported. The reaction is initiated in the presence of iodine by two successive nucleophilic additions of indoles with an aldehyde group of ortho-formylarylketones, and the ketone does not undergo a nucleophilic addition and only involves in the Friedel-Crafts-type cyclization. A variety of substrates are tested, and the efficiency of this reaction is demonstrated with gram-scale reactions.

Lewis Acid-Catalyzed 2,3-Dihydrofuran Acetal Ring-Opening Benzannulations toward Functionalized 1-Hydroxycarbazoles

The development of a Lewis acid-catalyzed, intramolecular ring-opening benzannulation of 5-(indolyl)2,3-dihydrofuran acetals is described. The resulting 1-hydroxycarbazole-2-carboxylates are formed in up to 90% yield in 1 h. The dihydrofuran acetals are readily accessed from the reactions of enol ethers and α-diazo-β-indolyl-β-ketoesters. To highlight the method's synthetic utility, a formal total synthesis of murrayafoline A, a bioactive carbazole-containing natural product, was undertaken.

One-Pot Synthesis of 1,2-Disubstituted Indoles from 2-Ethynylanilines and Benzaldehydes

An efficient synthesis of a variety of 1,2-disubstituted indoles from 2-ethynylanilines was developed. Using 2-ethynylanilines and benzaldehydes as starting materials, the target products (1,2-disubstituted indoles) were obtained smoothly through condensation, reduction, and subsequent cyclization. Various functional groups attached to the aryl ring of 1,2-disubstituted indoles were well tolerated. The protocol features easy performance, easily available starting materials, good yield, and a broad substrate scope, showing potential synthetic value for the preparation of a variety of biologically or pharmaceutically active compounds.

Benzocarbazole Synthesis via Visible-Light-Accelerated Rh(III)-Catalyzed C-H Annulation of Aromatic Amines with Bicyclic Alkenes

A visible-light-accelerated Rh(III)-catalyzed C-H annulation of aromatic amines with bicyclic alkenes for the synthesis of benzocarbazole derivatives was developed. In this approach, with the cooperation of rhodium catalysis and visible-light irradiation, various aromatic amines reacted with oxabicyclic alkenes and azabicyclic alkenes smoothly at room temperature, delivering the corresponding bridged oxa or aza tetrahydro benzocarbazoles in good to excellent yields. Moreover, a series of benzo[b]carbazoles were synthesized conveniently through further aromatization in one pot. The potential of this method was demonstrated via directing-group removal, derivatization, a scale-up reaction, and fluorescence investigations.