@article { ISI:000374104500001, title = {Synthesis and characterization of superhydrophobic-superoleophilic surface}, journal = {Journal of Sol-Gel Science and Technology}, volume = {78}, number = {3}, year = {2016}, month = {JUN}, pages = {475-481}, publisher = {SPRINGER}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

The binary superhydrophobic-superhydrophilic surface has been successfully achieved by a combination of nanoscale texture roughness on micro-textured cotton thread network by layer-by-layer deposition method through the single-step sol-gel route. Furthermore, microstructures with improved wettability were produced, in which silica nanotextures were grown without modifying the chemical method to form superoleophilic and superhydrophobic networks. A superoleophilic surface (oil contact angle 0A degrees) and a superhydrophobic coated cotton fabric with surface free energy of gamma (total) = 13. 23 +/- A 0.37 mJ m(-2) (water contact angle of 167 +/- A 1A degrees and a small sliding angle of 4 +/- A 1A degrees) were successfully obtained. The results were exemplified here by the creation of immiscible oils separation membranes, and the innumerable applications of this technology also include self-cleaning fabrics, antistaining fabrics, water purification, and antiwetting fabrics for military applications.

}, keywords = {contact angle, Layer-by-layer deposition method, sol-gel processing, Superhydrophobic-superoleophilic surface}, issn = {0928-0707}, doi = {10.1007/s10971-016-3974-7}, author = {Mahadik, Satish A. and Pedraza, Fernado D. and Relekar, Brahmanand P. and Parale, Vinayak. G. and Lohar, Gaurav M. and Thorat, Sagar S.} } @article {44192, title = {Synthesis of furo[2,3-b]pyran-2-ones through Ag(I)- or Ag(I)-Au(I)-catalyzed cascade annulation of alkynols and alpha-ketoesters}, journal = {Organic Letters}, volume = {20}, year = {2018}, month = {FEB }, pages = {872-875}, type = {Article}, abstract = {

Ag(I)- or Ag(I)-Au(I)-catalyzed cascade annulation of alkynols (5-hexyn-1-ol systems) with a-ketoesters involving a dual activation process (pi and sigma) has been developed for the first time. This reaction proceeds through cycloisomerization of alkynol to give the 6-endo-enol ether followed by annulation with an alpha-ketoester to furnish furo[2,3-b]pyran-2-ones in good yields. Chemical structures of all products were rigorously confirmed by single crystal X-ray analysis and analogy.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.7b04027}, author = {Thorat, Sagar S. and Kataria, Priyanka and Kontham, Ravindar} } @article {47659, title = {Stereoselective total synthesis of (+/-)-pleurospiroketals A and B}, journal = {Journal of Organic Chemistry}, volume = {86}, year = {2021}, month = {OCT }, pages = {13572-13582}, type = {Article}, abstract = {A full account of our efforts toward the stereoselective total synthesis of sesquiterpenoid-derived natural products (+/-)-pleurospiroketals A and B is described. Commercially available 3-methyl-2-cyclohexenone and 2,2-dimethyloxirane were used as key building blocks, and the substrate-controlled stereoselection was exploited to access the entire stereochemistry of these natural products. Initially, a planned synthetic route involving a [6,5]-bicyclic lactone intermediate was found to be insurmountable, and the later strategy comprising OsO4-NMO-mediated dihydroxylation of 3-methyl-2-cyclohexenone, followed by Luche reduction, Eschenmoser methylenation, and Bronsted acid-induced spiroketalization steps, was ultimately identified as the reliable strategy.}, issn = {0022-3263}, doi = {10.1021/acs.joc.1c01634}, author = {Thorat, Sagar S. and Krishna, Gamidi Rama and Kontham, Ravindar} } @article {47363, title = {Strategies for the synthesis of furo-pyranones and their application in the total synthesis of related natural products}, journal = {Organic Chemistry Frontiers}, volume = {8}, year = {2021}, month = {MAY}, pages = {2110-2162}, type = {Review}, abstract = {

The furo-pyranone framework is widely present in the molecular structure of various biologically potent natural products and un-natural small molecules, and it represents a valuable target in synthetic organic chemistry and medicinal chemistry. In the last five decades, numerous innovative synthetic methodologies have been disclosed for these bis-oxacyclic fused heterocycles, expanding the scope of accessible building blocks, efficient and affordable catalysis, facile reaction conditions, and overall practicality of the process. In this comprehensive review article, we focus on showcasing the complete spectrum (from the first report in the 1970s to the latest disclosure in 2020) of efforts devoted towards the synthesis of diverse classes of furo-pyranones through systematization and critical analysis of the accumulated experimental knowledge and their elegant applications in total syntheses of biologically interesting related natural products.

}, issn = {2052-4129}, doi = {10.1039/d0qo01421d}, author = {Thorat, Sagar S. and Kontham, Ravindar} } @article {47834, title = {Silver-catalyzed [3 + 3]-annulation cascade of alkynyl alcohols and α,β-unsaturated ketones for the regioselective assembly of chromanes}, journal = {Organic Chemistry Frontiers}, volume = {9}, year = {2022}, month = {JAN}, pages = {802-809}, type = {Article}, abstract = {An unprecedented Ag(i)-catalyzed [3 + 3]-annulation of alkynyl alcohols (5-hexyn-1-ols) and α,β-unsaturated ketones is reported to construct simple to complex chromanes. This transformation begins with hydroalkoxylation of alkynol through C{\textendash}C triple bond activation to give cyclic-enol ether, followed by intermolecular 1,4-addition and intramolecular 1,2-addition of enol ethers onto the enone and oxidative aromatization or Grob-type elimination steps. Facile reaction conditions, broad substrate scope, good to excellent yields, and atom economy are the salient features of this protocol. Isolation of the active pyran-tethered cyclohexadiene reaction intermediate, additional supporting experiments, and DFT calculations strongly support the experimental findings and corroborate our proposed mechanism.}, issn = {2052-4129}, doi = {10.1039/D1QO01643A}, author = {Nakate, Ashwini K. and Thorat, Sagar S. and Jain, Shailja and Rama Krishna, Gamidi and Vanka, Kumar and Kontham, Ravindar} } @article {49507, title = {Studies on the stereoselective synthesis of sacubitril via a chiral amine transfer approach}, journal = {Chemistry-An Asian Journal}, volume = {20}, year = {2025}, month = {MAR }, type = {Article}, abstract = {

We present a comprehensive account of our efforts directed towards the synthesis of sacubitril, a neprilysin inhibitor used in combination with valsartan and marketed as Entresto (TM). Our initial approach to the formal synthesis of sacubitril employed a chiral pool strategy, utilizing (S)-pyroglutamic acid as a key building block and Cu(I)-mediated Csp2-Csp3 cross-coupling as a key transformation. Further investigations led to the development of chiral amine transfer (CAT) reagents-based stereoselective synthesis. This involved the E-selective construction of gamma-ylidene-butenolide from readily available biphenyl bromide and 4-pentynoic acid, the conversion of this butenolide to its ene-lactam using chiral amine, and substrate-controlled diastereoselective reduction of ene-lactam using Et3SiH or Pd/C, H2 (overall chiral amine transfer) as key transformations. Antipodal lactam intermediates were synthesized using corresponding chiral amines, and the stereochemical outcomes during the ene-lactam reduction with Et3SiH were rationalized by DFT studies.

}, keywords = {Chiral Amine Transfer (CAT) approach, Chiral pool approach, Sacubitril, stereoselective synthesis}, issn = {1861-4728}, doi = {10.1002/asia.202401223}, author = {Sadanande, Megha V. and Thorat, Sagar S. and Sharma, Himanshu and Singh, Geetika and Vanka, Kumar and Gonnade, Rajesh G. and Kontham, Ravindar} }