Intermolecular C-H Aminocyanation of Indoles via Copper-iodine Cocatalyzed Tandem C-N/C-C Bond Formation

Iron-Catalyzed Friedel-Crafts-type 3,5-Diacylation of Indoles

The exploration of remote functionalization of indoles is impeded by the inherently dominant reactivity intrinsic to the pyrrole moiety. Herein, we delineate a novel strategy facilitated by Lewis acid mediation, enabling the remote C-H functionalization, which culminates in the synthesis of an array of selectively functionalized indole derivatives, encompassing 3-trifluoroacetyl and 5-benzoyl motifs, utilizing trifluoroacetic anhydride and various acyl chlorides. Notably, the protocol exhibits versatility, as epitomized by the extension of C5-acylation to alkylation and sulfonation reactions. This methodology is distinguished by its exemplary regio- and chemo-selectivity, extensive substrate scope, commendable tolerance to a diverse array of functional groups, and the employment of comparatively mild reaction conditions.

Organoselenium-Catalyzed C2,3-Diarylation of N-H Indoles

An organoselenium-catalyzed C2,3-diarylation of unprotected N-H indoles with electron-rich aromatics has been developed. This one-pot multicomponent tandem cross-dehydrogenation coupling reaction allows for the incorporation of two different aromatic groups to indoles. More importantly, this approach offers significant advantages, including a high atom and step economy, eliminating the need for prepreparation of the reaction substrates, streamlining the synthetic process and enhancing its practicality. Overall, this organoselenium-catalyzed C2,3-diarylation reaction presents an efficient and versatile strategy for the functionalization of indole derivatives.

Iodine-dependent oxidative regioselective aminochalcogenation of indolines

A directing-group-free strategy for oxidative regioselective aminochalcogenation of indolines with amines and dichalconides is presented. This strategy combines tandem coupling sequences and oxidative dehydrogenation methods in a multi-component reaction, enabling the fast construction of a series of C2,3- or C2,5-aminochalcogenated indole derivatives. Moreover, the application of this synthetic approach is demonstrated through the late-stage modification of pharmaceuticals and the derivatization of the products, highlighting its potential and significance.

Iodine-Mediated C2,3-H Aminoheteroarylation of Indoles

A metal-free one-pot oxidative cross-dehydrogenation coupling reaction for the formation of C-N/C-C bonds at the C2,3-positions of indoles with azoles and quinoxalinones has been developed. The proposed method has several notable features, including metal-free catalysis, the use of N-H free indoles as substrates, ease of operation, mild reaction conditions, and compatibility with a wide range of substrates.

Copper-Catalyzed Intermolecular Cross-dehydrogenative C-N Coupling at Room Temperature via Remote Activating Group Enabled Radical Relay Strategy

Employing N-fluorobenzenesulfonimide (NFSI) as a nitrogen-centered radical (NCR) precursor, an intermolecular C(sp²)-N coupling on heteroarenes or substituted benzenes with remote activated aniline derivatives via copper catalyzed N-N radical relay strategy at room temperature is developed. Good to excellent yields are acquired, and no ligand or additive is required. Reaction scope investigation and preliminary mechanistic studies demonstrate that the remote activating strategy and delicate control on the reactivities of active NCR species are essential to guarantee satisfactory chemo- and site-selectivity.

Iron–iodine co-catalysis towards tandem C–N/C–C bond formation: one-pot regioselective synthesis of 2-amino-3-alkylindoles

An efficient intermolecular C2,3-H aminoalkylation of indoles with 9H-xanthenes and azoles via iron–iodine co-catalyzed tandem C–N/C–C bond formation has been developed.