Direct Synthesis of 2-Acyl Acridines Using Aldimines and Anthranils: Evaluation of Cytotoxicity and Anti-Inflammatory Activity

Advances in transition metal-catalyzed C-H amination strategies using anthranils

Modern times have witnessed an uprise in the synthesis and derivatization of nitrogen-containing fused heterocycles. Amination reactions involving nitrene chemistry have always been the most convenient choice for the incorporation of a nitrogen atom in a molecule. The utilization of an open nitrene species harnesses harsh conditions. Hence, transition metal-catalyzed C-H amination reactions using aminating agents have been an attractive choice. Electrophilic aminating agents for C-H amination reactions are well exploited due to their desirable reaction conditions. Out of all, anthranils have paved the way forward due to their utility in simultaneously forming two new functional groups (amine and carbonyl). Amination using anthranils follows a metal-nitrenoid pathway. Often, the amination has been followed by a Lewis acid or transition metal-mediated intramolecular cyclization to directly produce fused heterocycles. This review broadly demonstrates the utilization of anthranils as an aminating agent for transition metal-catalyzed C-H amination reactions. The focus has been given to the scope, limitations, and mechanistic understanding of using such an electrophilic aminating agent, anthranil, with transition metals.

Cp*Co(III)-catalyzed C-H amination/annulation cascade of sulfoxonium ylides with anthranils for the synthesis of indoloindolones

Cp*Co(iii)-catalyzed [4+1] annulation of sulfoxonium ylides with anthranils has been developed for the synthesis of indole-indolone scaffolds. The dual functionality of anthranils was exploited, wherein the nitrogen has been used for C-H amination and the aldehyde group was utilized in the subsequent intramolecular aldol condensation to furnish the corresponding annulated products.

tert-Butyl Bromide-Promoted Intramolecular Cyclization of 2-Arylamino Phenyl Ketones and Its Combination with Cu-Catalyzed C-N Coupling: Synthesis of Acridines at Room Temperature

Herein, a facile intramolecular cyclization of 2-arylamino phenyl ketones is established to supersede the traditional high-temperature, strongly acidic conditions and achieve 9-substituted acridines, by virtue of the combination of 2,2,2-trifluoroethanol and tert-butyl bromide. This protocol can be merged well with the preceding Cu-catalyzed intermolecular Chan-Evans-Lam cross-coupling reactions, therefore enabling pot-economic modular synthesis of 9-substituted acridines from readily available 2-amino phenyl ketones and aryl boronic acids at room temperature.

Phthalazinone-Assisted C-H Amidation Using Dioxazolones Under Rh(III) Catalysis

The preparation of phthalazinone derivatives is pivotal for their utilization as pharmaceutical agents and other entities. Herein, we report the phthalazinone-assisted carbon-nitrogen bond forming reaction using dioxazolones as robust amidation sources under Rh(III) catalysis. The broad functional group tolerance and complete site-selectivity are observed. Notably, a series of transformations of synthesized compounds into biologically relevant N-heterocycles demonstrates the applicability of the developed methodology.

Anthranils: versatile building blocks in the construction of C–N bonds and N-heterocycles

This review article provides an overview of the recent progress in the transformations of anthranils, which have emerged as versatile building blocks in the assembly of various C–N bonds and medicinally active heterocyclic systems.