Synthetic Utility of Arylmethylsulfones: Annulative π-Extension of Aromatics and Hetero-aromatics Involving Pd(0)-Catalyzed Heck Coupling Reactions

Synthesis of di/tri-substituted carbazoles involving Pd-mediated Sonogashira coupling of indolyltriflates with aryl acetylenes

In this study, we present our preliminary findings on the synthesis of carbazole derivatives involving the Sonogashira coupling reaction of 2-(trimethylamino)methylindolyltriflates with aryl acetylenes followed by isomerization, thermal electrocyclization and 1,3-H shift, furnishing the respective di- and tri-substituted carbazoles.

Synthesis of Annulated Carbazoles via FeCl3/SnCl4‑Mediated Domino Reaction of Vinyl Ketone Tethered Bromomethylindoles with Arenes and Heteroarenes

One-pot synthesis of aryl- as well as heteroaryl-annulated carbazoles was achieved from 2/3-bromomethylindoles involving Lewis acid mediated domino reaction with arenes as well as heteroarenes via successive Friedel–Crafts intermolecular as well as intramolecular alkylations followed by elimination of acetone. Further, the bis-domino reaction of 2,5-bis(bromomethyl)pyrrole was also carried out with selected heteroarenes. Additionally, the synthesized thienocarbazoles and thieno­dibenzofurans were successfully utilized for a second-generation domino reaction.

Rh(III)-Catalyzed Oxidative C-2 Coupling of N-Pyridinylindoles with Benzo[b]thiophene 1,1-Dioxides via C-H Bond Activation

An efficient Rh(III)-catalyzed cross-dehydrogenative coupling of N-pyridinylindoles with benzo[b]thiophene 1,1-dioxides has been developed through directing-group-assisted C-H activation. This transformation constructs a new C-C bond from two inert C-H bonds in a one-pot reaction. The present reaction is compatible with various functional groups with respect to indoles and benzothiophene[b] 1,1-dioxides. Furthermore, the emission properties of synthesized compounds have been explored.

NMR characterization of rearranged staurosporine aglycone analogues from the marine sponge Damiria sp

The indolocarbazole family of bisindole alkaloids is best known for the natural product staurosporine, a protein kinase C inhibitor that belongs to the indolo[2,3-a]carbazole structural class. A large number of other indolo[2,3-a]carbazoles have subsequently been isolated and identified, but other isomeric forms of indolocarbazole natural products have rarely been reported. An extract of the marine sponge Damiria sp., which represents an understudied genus, provided two novel alkaloids named damirines A (1) and B (2). Their structures were assigned by comprehensive NMR spectroscopic analyses, and for compound 2, this included application of the LR-HSQMBC pulse sequence, a long-range heteronuclear correlation experiment that has particular utility for defining proton-deficient scaffolds. The damirines represent a new hexacyclic carbon-nitrogen framework comprised of an indolo[3,2-a]carbazole fused with either an aminoimidazole or a imidazolone ring. Compound 1 showed selective cytotoxic properties toward six different cell lines in the NCI-60 cancer screen.

Straight access to highly fluorescent angular indolocarbazoles via merging Au- and Mo-catalysis

A straightforward and efficient synthesis of the two less explored types of indolocarbazoles has been developed giving rise to highly fluorescent compounds with fluorescence quantum yields around 0.7.

Chemistry and Properties of Indolocarbazoles

The indolocarbazoles are an important class of nitrogen heterocycles which has evolved significantly in recent years, with numerous studies focusing on their diverse biological effects, or targeting new materials with potential applications in organic electronics. This review aims at providing a broad survey of the chemistry and properties of indolocarbazoles from an interdisciplinary point of view, with particular emphasis on practical synthetic aspects, as well as certain topics which have not been previously accounted for in detail, such as the occurrence, formation, biological activities, and metabolism of indolo[3,2- b]carbazoles. The literature of the past decade forms the basis of the text, which is further supplemented with older key references.