@article{KarrasDabrowskiPohletal.2018,
  author    = {Karras, Manfred and Dabrowski, Michal and Pohl, Radek and Rybacek, Jiri and Vacek, Jaroslav and Bednarova, Lucie and Grela, Karol and Stary, Ivo and Stara, Irena G. and Schmidt, Bernd},
  title     = {Helicenes as Chirality-Inducing Groups in Transition-Metal Catalysis},
  series = {Chemistry - a European journal},
  volume    = {24},
  journal   = {Chemistry - a European journal},
  number    = {43},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0947-6539},
  doi       = {10.1002/chem.201802786},
  pages     = {10994 -- 10998},
  year      = {2018},
  abstract  = {Helical chirality is a novel enantioselectivity-inducing property in transition-metal-catalyzed transformations. The principle is illustrated herein for the example of asymmetric olefin metathesis. This work reports the synthesis of the first helically chiral Ru-NHC alkylidene complex from an aminohelicene-derived imidazolium salt, which was ligated to the first generation Hoveyda-Grubbs catalyst. Kinetic data were acquired for benchmark test reactions and compared to an achiral catalyst. The helically chiral Ru-catalyst was evaluated in asymmetric ring-closing metathesis (RCM) and ring-opening metathesis-cross-metathesis (ROM/CM) reactions, which proceeded with promising levels of enantioselectivity. Extensive NMR-spectroscopic investigations and a DFT geometry optimization were performed. These results led to a topographic steric map and calculation of percent-buried-volume values for each quadrant around the metal center.},
  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}
}