Metal-free synthesis of N-fused quinazolino-quinazoline-diones as a RNA triple helix intercalator.

The development of chemical scaffolds that target highly conserved RNA received attention due to its significance in splicing, nuclear organization, and gene expression in disease progression pathways. Here, we synthesized a series of N-fused quinazolino-quinazoline-diones a PIDA-induced C-N coupling methodology to target . Interestingly, compound 2z binds to the UUG pocket of a RNA triple-helix through intercalation, evidenced from molecular docking studies, fluorescence-based assay and CD experiments.

Copper(II)-Mediated Dual Reactivity of 2-(5-Phenylisoxazol-3-yl)aniline: Directed Amination and Oxidative C(═O)─C Cleavage of Amides Enabling Direct Access to Urea Derivatives.

The dual reactivity of amides fused to 2-(5-phenylisoxazol-3-yl)aniline as a directing group for the formation of urea derivatives via chemospecific cleavage of the C(═O)─C bond and C(sp)-H amination is reported here. Employing inexpensive copper as the catalyst and O in air as the oxidant, this protocol exhibited broad functional group tolerance for both the transformations. Detailed mechanistic studies and DFT calculations were performed to gain insights into a plausible mechanism for the formation of urea derivatives.

Synthesis of N-Fused Triazole-Piperazine-Quinazolinones via One-Pot Tandem Click Reaction and Cross-Dehydrogenative Coupling.

Herein, a one-pot protocol to synthesize tetracyclic triazole-piperazine-quinazolinone-fused N-heterocyclic scaffolds is reported. In this strategy, a tandem approach of two highly efficient synthetic reactions, click and cross-dehydrogentive coupling reactions, with high atom economy were employed to obtain the target N-fused scaffolds. Being highly functional group tolerable, this method has broad substrate scope.

Synthetic and Computational Studies on Rh-Catalyzed Redox-Neutral Cascade of Carbenoid Functionalization and Dephosphonylative Annulation.

A Rh(III)-catalyzed regioselective redox-neutral cascade process of carbenoid functionalization followed by dephosphonylative annulation of benzoic acids with α-diazo-β-keto phosphonate has been realized, which led to the direct synthesis of a privileged 3-substituted isocoumarin scaffold. To the best of our knowledge, this is the first report of a complete redox neutral method to synthesize isocoumarins using C-H functionalization strategy. In the catalytic cycle of this reaction, there are two possible pathways for the C-C coupling between ortho-positioned carbon atom of benzoic acid and the diazo carbon atom: (i) concerted 1,2-aryl shift and (ii) stepwise metal-carbene formation followed by migratory insertion.