Chandrasekhar S

Biography

r Srivari Chandrasekhar is an excellent synthetic organic chemist and this is amply justified by 258 publications, 3 patents and ~5000 citations in various journals. His contributions in total synthesis of scarce marine natural products and organocatalysis are globally recognized. His noteworthy contributions in the total synthesis of architecturally diverse natural products are well-reflected towards the total synthesis of 35 natural products, which include an acinar morphogenetic inhibitor, Fusarisatin A, molecule with anticancer activity through tubulin inhibition, Rhazinal, neuro-protective natural product Stachybotrin C, anticancer molecule pladienolide, molecule with CNS activity, Kainic acid, prostacyclin analogue Beraprost, Bedaquiline (both R and S isomers) anti-TB compound, Azumamide E, Bengazole, Arenamide, Tubulysin, Spirastellolide B, Hyacinthacene A1, (-)-Spongidepsin with absolute stereo control. All these achievements were accomplished while developing new C–C bond formation reactions using organo-catalysis and carbocycles derived from carbohydrates. More prudent research field has been the identification of novel peptido-mimetics wherein research group of Dr. S. Chandrasekhar has synthesized β-sugar amino acids, norbornene-based, aminoxy acids of furanoses and nucleoside-based amino acids and demonstrated that these monomers in various combinations of oligomerization resulted in predefined secondary structures including nanotubes. Dr S. Chandrasekhar has for the first time identified polyethylene glycol (PEG) as a recyclable solvent for organo-metallic reactions wherein both the solvent and catalyst can be recycled. This unprecedented report triggered various research programs using PEG as a solvent in different parts of the world. Some of the reactions worth mentioning using PEG as solvent are as follows: Heck reaction in PEG, Sharpless asymmetric dihydroxylation (was performed for the first time in PEG), PtO2 recycle and H2 absorption studies. This work has found direct applications in developing non-infringing technologies for APIs. Dr S Chandrasekhar has never hesitated to take-up challenging process development subjects relevant to health care. The processes developed for semi-synthesis of Taxol (M/s. Cipla), Misoprostol (M/s. AVRA) and Carboprost (M/s. AVRA) are worth mentioning and biotech problems are also addressed by him as evident in the synthesis of Fondaparinux as anti-coagulant agent (Table 1). In addition, as part of the ‘Drug Discovery Process,’ over 500 new chemical entities are being synthesized in his group. The process developed for EV-077 sponsored by M/s. Evolva biotech helped them to enter into phase I clinical studies. Several combinatorial libraries were prepared in his group as new chemical entities for screening against cancer (US patent 7179937), TNFα, 5HT antagonism etc. Two review articles written by him on hybrid natural products (Angewandte Chemie 2003, 3996) and prostaglandins (Chemical Review, 2007, 3286) are worth mentioning. A recent contribution of Dr. S. Chandrasekhar is the synthesis of bedaquiline (2S)-R207910, a novel anti-tuberculosis molecule, which has appeared as cover page with theme “Chemistry for a healthy world” in Eur. J. Org. Chem. 2011, 2057. To date 50 students have already been awarded doctoral degree under his supervision and 20 students are pursuing their doctoral work on various themes in total synthesis, green chemistry, supramolecular chemistry, automation combinatorial chemistry and chemical biology.

Research Interest

Synthesis of scarce marine natural products and organocatalysis