@article{SchmidtSchultze2018,
  author    = {Schmidt, Bernd and Schultze, Christiane},
  title     = {A one-pot synthesis of pyranocoumarins through microwave-promoted propargyl claisen rearrangement/wittig olefination},
  series = {European journal of organic chemistry},
  volume    = {2018},
  journal   = {European journal of organic chemistry},
  number    = {2},
  publisher = {Wiley-VCH Verl.},
  address   = {Weinheim},
  issn      = {1434-193X},
  pages     = {223 -- 227},
  year      = {2018},
  abstract  = {The reaction between propargyl ethers of hydroxybenzaldehydes and the ylide ethyl (triphenylphosphoranylidene)acetate was carried out under microwave irradiation to regioselectively afford angular pyranocoumarins. The chromene and coumarin heterocyclic scaffolds were simultaneously formed in the same synthetic step without changing the reaction conditions. The natural products seselin, braylin, and dipetalolactone were among the products synthesized by this method.},
  language  = {en}
}
@article{SchultzeFossSchmidt2020,
  author    = {Schultze, Christiane and Foß, Stefan and Schmidt, Bernd},
  title     = {8-Prenylflavanones through microwave promoted tandem claisen rearrangement/6-endo-trig cyclization and cross metathesis},
  series = {European journal of organic chemistry},
  volume    = {2020},
  journal   = {European journal of organic chemistry},
  number    = {47},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1434-193X},
  doi       = {10.1002/ejoc.202001378},
  pages     = {7373 -- 7384},
  year      = {2020},
  abstract  = {Prenylated flavanones were obtained from ortho-allyloxy chalcones through a one-pot sequence of Claisen rearrangement and 6-endo-trig cyclization, followed by olefin cross metathesis of the intermediate allyl flavanones with 2-methyl-2-butene. The synthetic utility of this route is illustrated for the synthesis of several naturally occurring prenyl flavanones.},
  language  = {en}
}
@article{SchultzeSchmidt2019,
  author    = {Schultze, Christiane and Schmidt, Bernd},
  title     = {Functionalized Benzofurans via Microwave-Promoted Tandem Claisen-Rearrangement/5-endo-dig Cyclization},
  series = {Journal of heterocyclic chemistry},
  volume    = {56},
  journal   = {Journal of heterocyclic chemistry},
  number    = {9},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0022-152X},
  doi       = {10.1002/jhet.3671},
  pages     = {2619 -- 2629},
  year      = {2019},
  abstract  = {Ortho-allyloxy alkinyl benzenes undergo, upon microwave irradiation in dimethylformamide, a tandem sequence of Claisen-rearrangement and 5-endo-dig cyclization to furnish 7-allyl-substituted benzofurans. With terminal alkynes, chroman-4-ones and enaminoketones become the main products. A mechanistic proposal for this observation relies on a reaction of the starting material with the solvent dimethylformamide under the microwave conditions.},
  language  = {en}
}
@article{SchultzeSchmidt2018,
  author    = {Schultze, Christiane and Schmidt, Bernd},
  title     = {Prenylcoumarins in One or Two Steps by a Microwave-Promoted Tandem Claisen Rearrangement/Wittig Olefination/Cyclization Sequence},
  series = {The journal of organic chemistry},
  volume    = {83},
  journal   = {The journal of organic chemistry},
  number    = {9},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0022-3263},
  doi       = {10.1021/acs.joc.8b00667},
  pages     = {5210 -- 5224},
  year      = {2018},
  abstract  = {The one-pot synthesis of 8-prenylcoumarins from 1,1-dimethylallylated salicylaldehydes and the stabilized ylide [(ethoxycarbonyl)methylene]triphenylphosphorane under microwave conditions was found to have a limited scope. The sequence suffers from a difficult and sometimes low-yielding synthesis of the precursors and from a competing deprenylation upon microwave irradiation. This side reaction occurs in particular with electron rich arenes with two or more alkoxy groups at adjacent positions, a prominent substitution pattern in naturally occurring 8-prenylcoumarins. Both limitations of this one-step sequence were overcome by a two-step synthesis consisting of a microwave-promoted tandem allyl ether Claisen rearrangement/Wittig olefination and a subsequent olefin cross metathesis with 2-methyl-2-butene. The cross metathesis step proceeds with a high selectivity and yields exclusively the desired prenyl, rather than the alternative crotyl substituent. Several naturally occurring 8-prenylcoumarins that were previously inaccessible have been synthesized in good overall yields along this route.},
  language  = {en}
}
@article{SchultzeSchmidt2018,
  author    = {Schultze, Christiane and Schmidt, Bernd},
  title     = {Ring-closing-metathesis-based synthesis of annellated coumarins from 8-allylcoumarins},
  series = {Beilstein journal of organic chemistry},
  volume    = {14},
  journal   = {Beilstein journal of organic chemistry},
  publisher = {Beilstein-Institut zur F{\"o}rderung der Chemischen Wissenschaften},
  address   = {Frankfurt, Main},
  issn      = {1860-5397},
  doi       = {10.3762/bjoc.14.278},
  pages     = {2991 -- 2998},
  year      = {2018},
  abstract  = {8-Allylcoumarins are conveniently accessible through a microwave-promoted tandem Claisen rearrangement/Wittig olefination/cyclization sequence. They serve as a versatile platform for the annellation of five- to seven-membered rings using ring-closing olefin metathesis (RCM). Furano-, pyrano-, oxepino- and azepinocoumarins were synthesized from the same set of precursors using Ru-catalyzed double bond isomerizations and RCM in a defined order. One class of products, pyrano[2,3-f]chromene-2,8-diones, were inaccessible through direct RCM of an acrylate, but became available from the analogous allyl ether via an assisted tandem catalytic RCM/allylic oxidation sequence.},
  language  = {en}
}