Ganesan S/O Arasu
Email Address
29 results
Publication Search Results
Now showing 1 - 10 of 29
Publication Strategies for the dynamic integration of combinatorial synthesis and screening(1998-11-02) Ganesan, A.; INSTITUTE OF MOLECULAR & CELL BIOLOGYPublication Solid-phase synthesis of tetramic acids(1998-06-11) Kulkarni, B.A.; Ganesan, A.; INSTITUTE OF MOLECULAR & CELL BIOLOGYUpon treatment with base, N-acylated α-amino acids loaded on Wang resin undergo cyclative Claisen-type condensation to release the tetrarnic acid in high yield and purity. The use of tetrabutylammonium hydroxide as base simplifies product purification, as it can be scavenged by acidic Amberlyst A-15 ion exchange resin. The diversity of the tetramic acids can be further increased by reductive alkylation of the starting amino acid.Publication Solid-phase combinatorial synthesis of 4-hydroxyquinolin-2(1H)-ones(1998-08-27) Sim, M.M.; Lee, C.L.; Ganesan, A.; INSTITUTE OF MOLECULAR & CELL BIOLOGYCyanoacetic acid was loaded on Wang resin and C-acylated using acid anhydrides and triethylamine as base. Resin cleavage with concomitant decarboxylation produces β-keto nitriles. In the case of isatoic anhydrides, the resin-bound acylated intermediates undergo cyclative cleavage upon heating, leading to 4hydroxyquinolin-2(1H)-ones.Publication Solid-phase synthesis of N-acyl-N'-carbamoylguanidines(1998-12-24) Lin, P.; Ganesan, A.; INSTITUTE OF MOLECULAR & CELL BIOLOGYAmino acids immobilized on polystyrene-Wang or Rink amide resin were reacted with p-nitrophenyl chloroformate to give an activated urethane that was displaced by S-methylisothiourea. Following N-acylation with an acid chloride, the thiomethyl group was displaced by primary or secondary amines with the aid of mercury (II) chloride to yield the unsymmetrically substituted title compounds after resin cleavage.Publication Intermolecular conjugate addition of alkyl radicals on solid phase(1999) Zhu, X.; Ganesan, A.; INSTITUTE OF MOLECULAR & CELL BIOLOGYThe conjugate addition of alkyl radicals, generated photolytically from the corresponding Barton esters, to acrylate immobilized on solid-phase was investigated. Using cross-linked polystyrene, acrylic acid was loaded with either the Wang or Rink linkers, and the reactions were carried out with 10 equiv of Barton ester. The yields following resin cleavage by trifluoroacetic acid were comparable to Barton's solution-phase results. TentaGel resins gave approximately 15% poorer yields, possibly due to radical quenching by the poly(ethylene glycol) spacer. With the Barton ester from cyclopent-2-enylacetic acid, the initial product of conjugate addition is capable of further intramolecular cyclization followed by attack of a second acrylate chain, resulting in polymer cross-linking.Publication Total synthesis of the fumiquinazoline alkaloids: Solution-phase studies(2000-02-25) Wang, H.; Ganesan, A.; INSTITUTE OF MOLECULAR & CELL BIOLOGYBiomimetic total syntheses of glyantrypine, fumiquinazoline F, fumiquinazoline G, and fiscalin B were achieved in four steps from tryptophan methyl ester. In the key step, the anthranilamide residue in a linear tripeptide is dehydrated to a benzoxazine by reaction with triphenylphosphine, iodine, and a tertiary amine. The benzoxazines subsequently undergo rearrangement to the natural products via an amidine intermediate. This dehydrative oxazine to quinazoline route is applicable to a broad range of N-acylanthranilamides, including sterically hindered cases.Publication Solution-phase synthesis of a combinatorial thiohydantoin library(1997) Sim, M.M.; Ganesan, A.; INSTITUTE OF MOLECULAR & CELL BIOLOGYAn efficient one-pot three-component synthesis of thiohydantoins was developed. In the first step, amino acid esters were alkylated by imine formation with aldehydes and reduction by sodium triacetoxyborohydride. In the second step, an isothiocyanate was added together with a molar equivalent of triethylamine, leading to the thiohydantoin product in high yield and purity after an extractive aqueous workup. This procedure was used to generate a combinatorial library of over 600 discrete thiohydantoins on a 0.1 mmol scale. Sampling of 10% of this library showed the thiohydantoin to be the major product in all cases, with purities of 52-98% by HPLC analysis. The cyclization conditions can also be adapted to the synthesis of hydantoins.Publication A solid-phase equivalent of van Leusen's TosMIC, and its application in oxazole synthesis(1999-07) Kulkarni, B.A.; Ganesan, A.; INSTITUTE OF MOLECULAR & CELL BIOLOGYPolystyrene-SH resin, prepared from Merrifield resin in two steps, was converted to polystyrene-SO2-CH2-NC in three steps. This resin functions as a solid-phase equivalent of p-tolylsulfonylmethyl isocyanide (TosMIC). Thus, reaction with aromatic aldehydes and tetrabutylammonium hydroxide as base yields 5-aryloxazoles.Publication The Dimeric Steroid-Pyrazine Marine Alkaloids: Challenges for Isolation, Synthesis, and Biology(2008-04-29) Ganesan, A.; INSTITUTE OF MOLECULAR & CELL BIOLOGYPublication Solid-phase synthesis of potential protein tyrosine phosphatase inhibitors via the Ugi four-component condensation(1998-09-22) Li, Z.; Yeo, S.L.; Pallen, C.J.; Ganesan, A.; INSTITUTE OF MOLECULAR & CELL BIOLOGYA library of 108 α,α-difluoromethylenephosphonic acids was prepared by Ugi four-component condensation using Rink-NH2 resin, 4- [(diethoxyphosphinyl)difluoromethyl]benzoic acid, and a set of 18 aldehydes and 6 isonitriles. Following resin cleavage, the diethylphosphonate esters were hydrolyzed with trimethylsilyl bromide to yield the free acids which were assayed for inhibition of PTPα, PTPβ and PTPε.
- «
- 1 (current)
- 2
- 3
- »