@article{KruegerLinker2021,
  author    = {Kr{\"u}ger, Tobias and Linker, Torsten},
  title     = {Synthesis of gamma-spirolactams by Birch reduction of arenes},
  series = {European journal of organic chemistry},
  volume    = {2021},
  journal   = {European journal of organic chemistry},
  number    = {10},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1099-0690},
  doi       = {10.1002/ejoc.202100056},
  pages     = {1585 -- 1591},
  year      = {2021},
  abstract  = {A convenient method for the synthesis of gamma-spirolactams in only three steps is described. Birch reduction of inexpensive and commercially available aromatic carboxylic acids in the presence of chloroacetonitrile affords nitriles in moderate to good yields. Suitable precursors are methyl-substituted benzoic acids, naphthoic, and anthroic acid. Subsequent catalytic hydrogenation proceeds smoothly with PtO2 or Raney Ni as catalysts and lactams are isolated in excellent yields and stereoselectivities. Thus, up to 3 new stereogenic centers can be constructed as sole diastereomers from achiral benzoic acids. Furthermore, it is possible to control the degree of saturation at different pressures, affording products with 0, 1, or 2 double bonds. Overall, more than 15 new gamma-spirolactams have been synthesized in analytically pure form.},
  language  = {en}
}
@article{KruegerBramborgKellingetal.2021,
  author    = {Kr{\"u}ger, Tobias and Bramborg, Andrea and Kelling, Alexandra and Sperlich, Eric and Linker, Torsten},
  title     = {Birch Reduction of Arenes as an Easy Entry to γ-Spirolactones},
  series = {European journal of organic chemistry},
  volume    = {2021},
  journal   = {European journal of organic chemistry},
  number    = {46},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1434-193X},
  doi       = {10.1002/ejoc.202101018},
  pages     = {6383 -- 6391},
  year      = {2021},
  abstract  = {A convenient method for the synthesis of γ-spirolactones in only 2-3 steps is described. Birch reduction of inexpensive and commercially available aromatic carboxylic acids in the presence of ethylene oxide affords hydroxy acids, which undergo direct lactonization during work-up. Suitable precursors are methyl-substituted benzoic acids, naphthoic, and dicarboxylic acids. Subsequent hydrogenation proceeds smoothly with Pd/C as catalyst and saturated γ-spirolactones are isolated in excellent yields and stereoselectivities. Thus, up to 3 new stereogenic centers can be constructed as sole diastereomers from achiral benzoic acids. Furthermore, it is possible to control the degree of saturation with Raney nickel or Wilkinson's catalyst to obtain products with 1 double bond. Overall, more than 30 new γ-spirolactones have been synthesized in analytically pure form.},
  language  = {en}
}
@article{KruegerKellingSchildeetal.2016,
  author    = {Kr{\"u}ger, Tobias and Kelling, Alexandra and Schilde, Uwe and Linker, Torsten},
  title     = {Simple Synthesis of gamma-Spirolactams by Birch Reduction of Benzoic Acids},
  series = {European journal of organic chemistry},
  journal   = {European journal of organic chemistry},
  number    = {6},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1434-193X},
  doi       = {10.1002/ejoc.201601650},
  pages     = {1074 -- 1077},
  year      = {2016},
  abstract  = {A convenient synthesis of gamma-spirolactams in only two steps was developed. Birch reduction of benzoic acids and immediate alkylation with chloroacetonitrile afforded cyclohexadienes in high yields. The products could be isolated by crystallization on a large scale in analytically pure form. Subsequent hydrogenation with platinum(IV) oxide as the catalyst reduced the nitrile functionality and the double bonds in the same step with excellent stereoselectivity. The relative configurations were determined unequivocally by X-ray analyses. Direct cyclization of the intermediary formed amino acids afforded the desired gamma-spirolactams in excellent overall yields. The procedure is characterized by few steps, cheap reagents, and can be performed on a large scale, interesting for industrial processes.},
  language  = {en}
}
@misc{VankarLinker2015,
  author    = {Vankar, Yashwant D. and Linker, Torsten},
  title     = {Recent Developments in the Synthesis of 2-C-Branched and 1,2-Annulated Carbohydrates},
  series = {European journal of organic chemistry},
  journal   = {European journal of organic chemistry},
  number    = {35},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1434-193X},
  doi       = {10.1002/ejoc.201501176},
  pages     = {7633 -- 7642},
  year      = {2015},
  abstract  = {The importance of carbohydrate chemistry in biological and medicinal chemistry has led to enormous developments in the synthesis of carbohydrate mimics. In this context, the synthesis of branched sugars in general and of 2-C-branched carbohydrates in particular, as well as the synthesis of 1,2-annulated sugars, have received immense attention. They serve not only as carbohydrate mimics in the form of stand-alone molecules, but also as useful intermediates in the synthesis of many natural products, their analogues, and glycosidase inhibitors. This microreview covers the recent synthetic efforts in this area and puts the subject matter into proper perspective for future developments.},
  language  = {en}
}
@article{YinLinker2011,
  author    = {Yin, Jian and Linker, Torsten},
  title     = {Stereoselective diversity-oriented syntheses of functionalized saccharides from bicyclic carbohydrate 1,2-lactones},
  series = {Tetrahedron},
  volume    = {67},
  journal   = {Tetrahedron},
  number    = {13},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0040-4020},
  doi       = {10.1016/j.tet.2011.01.069},
  pages     = {2447 -- 2461},
  year      = {2011},
  abstract  = {Bicyclic carbohydrate 1,2-lactones have been synthesized in only two steps and high yields by saponification and subsequent cyclization from known malonate addition products to glycals. The gluco-configured lactone serves as an important precursor for diversity-oriented syntheses. Thus, stereoselective opening of the lactone ring was realized with various nucleophiles in the presence of Sc(OTf)(3). This enabled the introduction of different substituents at the anomeric position, to afford a broad variety of 1-functionalized carbohydrates. On the other hand, stereoselective alpha-substitution of the gluco-configured lactone with different electrophiles and subsequent ring opening gives a collection of 2-functionalized saccharides. More than 30 products have been isolated in analytically pure form, and their configurations were unequivocally established by various NMR methods. Thus, carbohydrate 1,2-lactones are attractive precursors for the stereoselective synthesis of diverse saccharides.},
  language  = {en}
}
@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{BramborgLinker2012,
  author    = {Bramborg, Andrea and Linker, Torsten},
  title     = {Regioselective synthesis of alkylarenes by two-step ipso-substitution of aromatic dicarboxylic acids},
  series = {European journal of organic chemistry},
  journal   = {European journal of organic chemistry},
  number    = {28},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1434-193X},
  doi       = {10.1002/ejoc.201200823},
  pages     = {5552 -- 5563},
  year      = {2012},
  abstract  = {A strategy for the regioselective alkylation of arenes was developed, starting from commercially available and inexpensive terephthalic acid or naphthalene-1,4-dicarboxylic acid. The method entails a formal ipso-substitution of the carboxylate groups by a sequence of reductive alkylation under Birch conditions and subsequent acid-mediated rearomatization with loss of carbon monoxide and carbon dioxide. More than 20 different arenes with various side-chains were synthesized. With naphthalene-1,4-dicarboxylic acid as starting material, we were able to control the degree of alkylation by choosing the appropriate electrophile in the Birch reduction. Thus, bisalkylated naphthalenes and naphthoic acids became available chemoselectively. All reactions afforded a single regioisomer exclusively in high yields. Overall, aromatic dicarboxylic acids are suitable substrates for a two-step ipso-substitution that allows the selective synthesis of alkylated benzenes and naphthalenes.},
  language  = {en}
}
@article{WessigMatthesSchildeetal.2013,
  author    = {Wessig, Pablo and Matthes, Annika and Schilde, Uwe and Kelling, Alexandra},
  title     = {Asymmetric synthesis of (1,5)Naphthalenophanes by Dehydro-Diels-Alder reaction},
  series = {European journal of organic chemistry},
  journal   = {European journal of organic chemistry},
  number    = {11},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1434-193X},
  doi       = {10.1002/ejoc.201201594},
  pages     = {2123 -- 2129},
  year      = {2013},
  abstract  = {An asymmetric variant of the dehydro-Diels-Alder (DDA) reaction has been developed and applied in the atropselective synthesis of various (1,5)naphthalenophanes. Whereas the suitability of the photochemically induced DDA (PDDA) was limited, the thermally induced DDA provided the desired product, depending on the chiral auxiliary used and the length of the linker, with nearly perfect stereoselectivity. Furthermore, the mechanism of the DDA was investigated by means of DFT calculations, and a stepwise mechanism involving 1,4-biradicals was suggested.},
  language  = {en}
}
@phdthesis{Issaree2008,
  author    = {Issaree, Arisara},
  title     = {Synthesis of Hetero-chitooligosaccharides},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17069},
  school      = {Universit{\"a}t Potsdam},
  year      = {2008},
  abstract  = {Chitooligosaccharides are composed of linear β-(1→4)-linked 2-acetamido-2-deoxy-β-D-glucopyranose (GlcNAc) and/or 2-amino-2-deoxy-β-D-glucopyranose (GlcN). They are of interest due to their remarkable biological properties including antibacterial, antitumor, antifungal and elicitor activities. They can be obtained from the aminoglucan chitosan by chemical or enzymatic degradation which obviously affords rather heterogenous mixtures. On the other hand, chemical synthesis provides pure compounds with defined sequences of GlcNAc and GlcN monomers. The synthesis of homo- and hetero-chitobioses and hetero-chitotetraoses is described in this thesis. Dimethylmaleoyl and phthaloyl groups were used for protection of the amines. The donor was activated as the trichloroacetimidate in order to form the β-linkages. Glycosylation in the presence of trimethylsilyl trifluoromethanesulfonate, followed by N- and O-deprotection furnished chitobioses and chitotetraoses in good yields.},
  language  = {en}
}