@article{WangWangHuetal.2015,
  author    = {Wang, Xuebin and Wang, Xiaoli and Hu, Jing and Wang, Zhaoya and Pimpalpalle, Tukaram M. and Linker, Torsten and Yin, Jian},
  title     = {Study on the Synthesis of Novel Sugar Amino Acids},
  series = {Acta chimica Sinica = Huaxue-xuebao},
  volume    = {73},
  journal   = {Acta chimica Sinica = Huaxue-xuebao},
  number    = {7},
  publisher = {Science China Press},
  address   = {Beijing},
  issn      = {0567-7351},
  doi       = {10.6023/A15030205},
  pages     = {699 -- 704},
  year      = {2015},
  abstract  = {Sugar amino acids (SAAs) are carbohydrate derivatives bearing both amino and carboxylic acid functional groups. SAAs represent an important class of multifunctional building blocks, which are amenable to serve as glycomimetics or peptidomimetics with well-defined structures and useful properties. Because SAAs exist in nature in many forms with various biological activities, recently, many unnatural SAAs, as the demand for finding new molecules to discover new drugs and new materials, have been designed and synthesized by a number of research groups. In this paper, we have developed a convenient method for the synthesis of novel SAAs gluco-7 and galacto-7 for the first time. The structure of gluco-7 was similar to the natural SAA glucosaminuronic acid that was a component of many typical bacterial cell walls and could be used for the preparation of type D flu vaccine; while galacto-7 was similar to the natural SAA galactosaminuronic acid that was one of bacterial Vi-antigen components of Escherichia coli. Starting from unexpensive and commercially available 3,4,6-tri-O-acetyl-D-glucal and 3,4,6-tri-O-acetyl-D-galactal, two novel SAAs gluco-7 and galacto-7 were achieved in the linear 6 steps with 34\% overall yield and 19\% overall yield, respectively. The key reactions included radical addition, decarboxylation, iodine generation reaction, azide reaction and reductive amination reaction. The crucial step was the synthesis of the target compound gluco-7 from gluco-6. By using method A, the target compound gluco-7 was obtained in 4 steps with 63\% overall yield. To optimize the transformation from gluco-6 to gluco-7, method B was developed to generate gluco-7 by using one-pot reaction successfully with 76\% yield only in one step. It proved that method B was superior to method A with shorter steps and higher yields. All the new compounds were characterized by IR, H-1 NMR, C-13 NMR and HRMS data. Study on the synthesis and biological evaluation of linear and cyclic oligomers derived from gluco-7 and galacto-7 are currently in progress.},
  language  = {zh}
}
@article{VidadalaPimpalpalleLinkeretal.2011,
  author    = {Vidadala, Srinivasa Rao and Pimpalpalle, Tukaram M. and Linker, Torsten and Hotha, Srinivas},
  title     = {Gold-Catalyzed reactions of 2-C-Branched carbohydrates mild glycosidations and selective anomerizations},
  series = {European journal of organic chemistry},
  journal   = {European journal of organic chemistry},
  number    = {13},
  publisher = {Wiley-Blackwell},
  address   = {Malden},
  issn      = {1434-193X},
  doi       = {10.1002/ejoc.201100134},
  pages     = {2426 -- 2430},
  year      = {2011},
  abstract  = {2-C-branched methyl glycosides react with various alcohols under gold catalysis to transglycosylated products. The method is applicable for the convenient synthesis of disaccharides. Without nucleophile a selective anomerization occurs, giving first access to alpha-configured 2-C-nitromethyl glycosides. The results are interesting for the mechanism of gold-catalyzed glycosidations.},
  language  = {en}
}
@article{PimpalpalleYinLinker2012,
  author    = {Pimpalpalle, Tukaram M. and Yin, Jian and Linker, Torsten},
  title     = {Barton radical reactions of 2-C-branched carbohydrates},
  series = {Organic \& biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry},
  volume    = {10},
  journal   = {Organic \& biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry},
  number    = {1},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1477-0520},
  doi       = {10.1039/c1ob06370g},
  pages     = {103 -- 109},
  year      = {2012},
  abstract  = {Barton esters have been introduced into the side chain of carbohydrates with high yields in only a few steps from easily available glycals. Their radical reactions afford 2-C-methyl and 2-C-bromomethyl hexoses, pentoses and disaccharides in good yields in analytically pure form. Since the Barton esters have been synthesized by an oxidative radical addition and their transformations by reductive radical processes, our results demonstrate the power of such reactions in carbohydrate chemistry.},
  language  = {en}
}
@article{PimpalpalleVidadalaHothaetal.2011,
  author    = {Pimpalpalle, Tukaram M. and Vidadala, Srinivasa Rao and Hotha, Srinivas and Linker, Torsten},
  title     = {Lewis acid-catalyzed stereoselective lactonization and subsequent glycosidation of 2-C-malonyl carbohydrates},
  series = {Chemical communications},
  volume    = {47},
  journal   = {Chemical communications},
  number    = {37},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1359-7345},
  doi       = {10.1039/c1cc13425f},
  pages     = {10434 -- 10436},
  year      = {2011},
  abstract  = {Gold(III) bromide is a suitable catalyst for the stereoselective cyclization of 2-C-malonyl carbohydrates to the anomeric center under retention of one ester group. Reopening of the lactones with alcohols in the presence of TMSOTf affords allyl, propargyl and benzyl glycosides with high alpha-selectivity.},
  language  = {en}
}