Welcome to RK Group
π-Activation and
Natural Products (Asymmetric) Synthesis Lab
Organic Chemistry Division
CSIR-National Chemical Laboratory, Pune, INDIA
Dr. Ravindar Kontham
Principal Scientist-CSIR/Associate Professor-AcSIR
Division of Organic Chemistry
CSIR-National Chemical Laboratory
Dr. Homi Bhabha Road Pune-411008, India.
Phone Office: +91-20-2590 2301
Mobile: +91 750 788 9557
e-mail: k.ravindar@ncl.res.in/ konthamravindar@gmail.com
Dear Friends! Welcome to our website! Our research group is actively working in organic synthesis and medicinal chemistry. Our primary research focuses on cool projects like a practical stereo-selective total synthesis of complex biologically potent natural products and medicinal chemistry. We investigate to preparation more powerful, less toxic, and structurally simplified analogs of various complex natural products via structural modification of natural parent molecules. We also work on developing new synthetic methodologies involving π-activation induced cycloisomerization of alkynes and cascade polycyclizations.
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Natural products have long been regarded as ‘nature’s medicine chest,’ providing a rich source of lead compounds as invaluable platforms for developing front-line drugs. 63% of all new drugs approved by the FDA between 1981 and 2006 were inspired by natural products. Our research focuses on making and modifying naturally occurring bioactive compounds that have been isolated from plants, animal tissue, microbes, or marine and soil organisms, which are rare or hard to isolate in abundance. These compounds provide rich and diverse chemical structures that challenge the synthetic chemist to develop a new flexible synthetic methodology for their construction. Preparing synthetic analogs of the natural compound may improve biological activity and provide an understanding of the mechanism of action of the naturally occurring compound.
Recent Publications
Ready Access to [5,6,5]-Trioxa-spiro and Fused Ketals via Ag-Catalyzed Cascade Annulation of 4-Pentyn-1-ols and Aldehydes
Vinodkumar, R.; Nakate, A. K.; Krishna, G. R.; Kontham, R. Org. Lett. 2024, 26, 7116-7121.
Brønsted Acid-Promoted Cyclodimerization of α,β-Unsaturated γ-Ketoesters :Construction of Fused Pyrano-ketal-lactones and γ-Ylidene-butenolides
Vinodkumar, R.; Nakate, A. K.; Sharma, H.; Vanka, K.; Krishna, G. R.; Kontham, R. ACS Omega, 2024, 9, 19859-19878. DOI: https://doi.org/10.1021/acsomega.3c08873.
Rathod, A.; Borade, B.; Sambherao, P.; Kontham, R. Org. Biomol. Chem., 2024, 22, 496-500.
Kallure, G.; Sahoo, S.; Kale, R.; Barvkar, V.; Kontham, R.; Giri, A. Insect Biochemistry and Molecular Biology. 2024, 165, 104070. DOI: https://doi.org/10.1016/j.ibmb.2024.104070
Nakate, A.; Kataria, P.; Sambherao, P.; Krishna, G,R.; Kontham, R. Chem. Commun., 2024, 60, 1144-1147. DOI: https://doi.org/10.1039/D3CC05599J
Sahoo, S.S.; Kataria, P.; Kontham, R.; Org. Biomol. Chem., 2024, 22, 1475-1483. DOI: https://doi.org/10.1039/D3OB01924A
Thorat, S.S; Shimpi, S.P.; Sambherao, P.; Krishna, G.R.; Kontham, R. J. Org. Chem., 2023, https://doi.org/10.1021/acs.joc.3c01751
Kambale, D.; Borade, B.R.; Vinodkumar, R.; Kontham, R. J. Org. Chem., 2023, J. Org. Chem. 2023, 88, 12597−12612.
Navale, V. D.; Borade, B. R.; Krishna, G.R.; Vamkudoth, K.R.; Kontham. R. ACS Omega, 2023, 8, 36628-36635.
Kataria, P.; Sahoo, S. S.; Kontham. R. J. Org. Chem., 2023, 88, 7328-7346.
https://doi.org/10.1021/acs.joc.3c00549
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Pratapure, M. S.; Kontham,R. Tetrahedron Lett. 2023, 114, 154724.
Studies Directed Toward the Total Synthesis of Nannocystin A
Nomula, R.; Pratapure, M. S.; Kontham. R. ChemistrySelect 2022, 7, e202203893
Concise Total Synthesis of (+)-Lanceolactone A: Revision of Absolute Stereochemistry
Borade, B. R.; Kontham, R.; J. Org. Chem., 2022, 87, 12867-1287.
Enceleamycins A–C, Furo-Naphthoquinones from Amycolatopsis sp. MCC0218: Isolation, Structure Elucidation, and Antimicrobial Activity
Khan, A.; Said, M. S.; Borade, B. R.; Gonnade, R.; Barvkar, V.; Kontham, R.; Dastager, S. G. J. Nat. Prod., 2022, 85, 1267-1273.
Ready Access to Benzannulated [5,5]-Oxaspirolactones Using Au(III)-Catalyzed Cascade Cyclizations
Mankad, Y.; Thorat, S. S.; Das, P.; Gamidi, R. K.; Kontham, R.; Reddy, D. S. J. Org. Chem. 2022, 87, 3025–3041.
Silver-catalyzed [3+3]-annulation cascade of alkynyl alcohols and α,β-unsaturated ketones for the regioselective assembly of chromanes
Nakate, A. K.; Thorat, S. S.; Jain, S.; Krishna G.; Vanka, K.; Kontham, R. Org. Chem. Front, 2022, 9, 802-809.
Studies directed toward the synthesis of hedycoropyrans: total synthesis of des-hydroxy (-)-hedycoropyran B (ent-rhoiptelol B)
Kataria, P.; Nomula, R.; Kontham, R. Org. Biomol. Chem., 2022, 20, 444-463.
Stereoselective Total Synthesis of (±)-Pleurospiroketals A and B
Thorat, S. S.; Krishna G.; Kontham, R. J. Org. Chem., 2021, 86, 13572-13582.
Bismuth(III)-catalyzed bis-cyclization of propargylic diol-esters: a unified approach for the synthesis of [5,5]- and [6,5]-oxaspirolactones
Kambale, D. A.;Borade, B. R.;Kontham, R. Org. Biomol. Chem., 2021, 19, 6618-6622.
Strategies for the synthesis of furo-pyranones and their application in the total synthesis of related natural products
Thorat, S. S.; Kontham, R. Org. Chem. Front, 2021, 8, 2110-2162.
Total Synthesis of Beshanzuenone D & It's Epimers and Abiespiroside A
Borade, B. R.; Ruchi Dixit.;Kontham, R. Org. Lett., 2020, 22, 8561-8565.
Recent advances in the synthesis of oxaspirolactones and their application in the total synthesis of related natural products
Thorat, S. S.; Kontham, R. Org. Biomol. Chem., 2019, 17, 7270-7292.
TiCl4-n-Bu3N-mediated cascade annulation of ketones with α-ketoesters: a facilesynthesis of highly substituted fused γ-alkylidene-butenolides
Palange, M. N.; Gonnade, R. G.;Kontham, R. Org. Biomol. Chem., 2019, 17, 5749-5759.
Fe(III)-Catalyzed Diastereoselective Friedel−Crafts Alkylation−Hemiketalization−Lactonization Cascade for the Synthesis of Polycyclic Bridged 2‑Chromanol Lactones
Borade, B. R.; Nomula, R.; Gonnade, R. G.;Kontham, R. Org. Lett., 2019, 21, 2629-2633.
Four-Step Total Synthesis of (+)-Yaoshanenolides A and B
Thorat, S. S.; Palange, M. N.; Kontham, R. ACS Omega. 2018, 3, 7036-7045.
Bismuth(III)-catalyzed cycloisomerization and (hetero)arylation of alkynols: a simple access to 2-(hetero)aryl tetrahydrofurans and tetrahydropyrans
Nakate, A. K.; Pratapure, M. S.; Kontham, R. Org. Biomol. Chem., 2018, 16, 3229-3240.
Synthesis of Furo[2,3‑b]pyran-2-ones through Ag(I)- or Ag(I)−Au(I)-Catalyzed Cascade Annulation of Alkynols and α‑Ketoesters
Thorat, S.S.; Kataria, P.; Kontham, R. Org. Lett. 2018, 20, 872-875.
Lewis acid catalyzed cascade annulation of alkynols with α-ketoesters: a facile access to γ-spiroketal-γ-lactones
Kambale, D. A.;Thorat, S. S.; Pratapure, M. S.; Gonnade, R. G.;Kontham, R. Chem. Commun., 2017, 53, 6641-6144.