Showing papers by "Srivari Chandrasekhar published in 2018"

Syntheses of 2-Aroyl Benzofurans through Cascade Annulation on Arynes

Abstract: The highly efficient and expedient route for the syntheses of 2-aroyl benzofurans has been developed via the cascade [2+2] followed by a [4+1] annulation on arynes. The overall transformation proceeded through the formation of ortho-quinone methide by the insertion of transient aryne into N,N-dimethylformamide and subsequent trapping with sulfur ylide. Moreover, this transformation has a broad range of substrate scope with a high functional-group tolerance. This new reaction was successfully utilized in the synthesis of the potent CYP19 aromatase inhibitor and late-stage functionalization on the bioactive complex estrone.

Synthetic Strategy toward the Pentacyclic Core of Melodinus Alkaloids.

Abstract: The three-component Povarov reaction is efficiently utilized for construction of the pentacyclic framework of complex Melodinus alkaloids, which is amenable to expansion to other complex natural products. The key steps were Povarov reaction, one-pot reductive cyclization, and ring-closing metathesis (RCM) reaction.

Total Synthesis of Desmethyl Jahanyne and Its Lipo-Tetrapeptide Conjugates Derived from Parent Skeleton as BCL-2-Mediated Apoptosis-Inducing Agents.

Abstract: The total synthesis of highly potent and scarcely available marine natural product (−)-jahanyne was attempted resulting in a solution-phase synthesis of pruned versions with comparable activity. A simple and facile synthetic route was employed for the preparation of pruned congeners and would be scalable. The lipophilic tail of the natural product was synthesized from R-(+)-citronellol, utilizing easily available chemicals. All the synthesized compounds were screened for apoptotic activity against a panel of cell lines. These compounds depicted marked binding to B cell lymphoma 2 till 50 °C in cellular thermal shift analysis.

Synthesis of Asthma Drug Zafirlukast (Accolate) Using Intramolecular Oxidative Coupling via sp3 C-H Bond Activation.

Abstract: The FDA-approved drug for the treatment of asthma, zafirlukast, is synthesized engaging multiple catalytic reactions including a new method for the construction of 3-aroylindoles via oxidative cyclization. The highlights include transition-metal and peroxide free C–H bond activation using the stoichiometric amount of sodium persulfate as an oxidizing agent in the construction of 3-aroylindole, avoiding transition metal, with over 28% overall yield. The complete process has a turnaround time of 28 h to get the target molecule starting from substituted aniline, with practically no protecting groups.

Stereoselective Synthesis of Northern Fragment of Eribulin Mesylate from d-Mannose

Abstract: Stereoselective synthesis of northern fragment of eribulin mesylate is reported by coupling of the C1–C13 fragment with the C28–C35 fragment. The key steps involved in this synthesis are butyllithium-facilitated coupling between sulfone and aldehyde, then Dess–Martin periodinane oxidation followed by samarium(II) iodide mediated desulfonylation.

Spirooxindole compounds as gsk3β inhibitors and process for preparation thereof

Abstract: The present invention provides a compound of general formulae I useful as GSK3β inhibitors and their anticancer potential and process for preparation of these spirooxindoles. Formula I wherein Z is hydrogen, halogen, hydroxy, alkoxy, cyano, nitro; Ring A is a five membered or six membered or seven membered optionally containing additional hetero atom in the ring X is optionally CH2 Ring B is triazole or cyclic amine alone or with one or more hetero atoms part of the ring and optionally substituted with one or more substituents Y is hydrogen, alkoxy, aryloxy, hydroxy, ester, amide, amino, alkyl or aryl, heteroaryl, wherein these substituents are optionally substituted with one or more halogen, hydroxy, alkoxy, alkyl, aryl, heteroaryl, aryloxy, nitro, cyano, ester, aldehyde, wherein these substituents are further substituted with one or more halogen, hydroxy, alkoxy, alkyl, aryl, heteroaryl, aryloxy, nitro, cyano, ester, aldehyde.

Discovery and Development of Neuroprotective Agents from Natural products:Natural Product Drug Discovery

Abstract: This book discusses about recent developments in the area of neuroprotective natural products with respect to their isolation, characterization, and their pharmaceutical applications in the area of neurodegenerative diseases. In the first of 12 chapters, the author gives a brief outline of the book and summarizes the contents presented in each chapter.