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Herein, we describe a base‐promoted regioselective and chemoselective cascade cyclization, ynamide N−Csp bond cleavage, selective intramolecular 1,3‐migration, and simultaneous N‐desulfonylation strategy for the synthesis of 2‐phenyl‐3‐(phenylethynyl)‐1H‐indole derivatives. We observed multiple bond breaking (−N−Ts, and Csp2−Ts, Csp2−I/Csp2−SePh) from (E)‐3‐(1‐iodo‐2‐phenyl‐2‐tosylvinyl)‐2‐phenyl‐1‐tosyl‐indole/(E)‐2‐phenyl‐3‐(2‐phenyl‐1‐(phenylselanyl)‐2‐tosylvinyl)‐1‐tosyl‐indole derivatives to prepare 2‐phenyl‐3‐(phenylethynyl)‐1H‐indole in 15–60 min using our standard reaction conditions. A gram‐scale experiment as well as postsynthetic transformations of the synthesized 2‐phenyl‐3‐(phenylethynyl)‐1H‐indole were performed to exhibit the advantages of this synthetic methodology. [ABSTRACT FROM AUTHOR]

Environmentally friendly acid-catalyzed ynamide N–Csp bond cleavage, skeletal rearrangement and chemo-, regio- and stereospecific functionalization with nucleophiles are of great interest in synthetic chemistry. However, such transformations present remarkable regio- and stereospecific challenges due to the biased carbon–carbon (α and β) triple bonds in ynamides. Herein, we developed a greener and faster acid-catalyzed ynamide N–Csp bond fission, skeletal rearrangement and stereospecific functionalization with nucleophilic anisole derivatives to produce thermodynamically unstable challenging cis-alkene tethered indole scaffolds in a very short reaction time (5–10 min). The key features of this transformation are its transition-metal-free nature, broad scope, ease of handling, simple setup, mild reaction conditions, atom/step/time economy, and the gram-scale experiment. Most importantly, 13C-isotope labeling experiments in mechanistic studies confirmed the alkyne-carbon position in the rearrangement process. The green chemistry metrics evaluation and EcoScale score (75 on a scale of 0–100) indicate that our transformation is safer, environmentally friendly, and economically feasible. [ABSTRACT FROM AUTHOR]

To date, viruses are known to cause chronic to acute pathogenesis. Nevertheless, antiviral drugs have been known for their medicinal applications for the last few decades to treat infections caused by these pathogens. Despite advancements in the field of vaccination and antiviral drugs, there is a need for a molecule that can eradicate or control viral infection without getting resistance from pathogens will be a real challenge. This review covers possible ways to treat viral infections with pyrimidine and its mimics compared to known antiviral drugs. A comprehensive study of the report accomplished synthetic routes of pyrimidine analogs and their target‐specific antiviral potential. The present review article covers literature from 2018 to 2022. [ABSTRACT FROM AUTHOR]