@article{KarrasHolecBednarovaetal.2018,
  author    = {Karras, Manfred and Holec, Jan and Bednarova, Lucie and Pohl, Radek and Schmidt, Bernd and Stara, Irena G. and Stary, Ivo},
  title     = {Asymmetric Synthesis of Nonracemic 2-Amino[6]helicenes and Their Self-Assembly into Langmuir Films},
  series = {The journal of organic chemistry},
  volume    = {83},
  journal   = {The journal of organic chemistry},
  number    = {10},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0022-3263},
  doi       = {10.1021/acs.joc.8b00538},
  pages     = {5523 -- 5538},
  year      = {2018},
  abstract  = {Alternative ways of preparing nonracemic 2-amino[6]helicene derivatives were explored. The enantioselective [2 + 2 + 2] cycloisomerization of a nonchiral triyne under Ni(cod)(2)/(R)-QUINAP catalysis delivered the enantioenriched (+)-(P)-2-aminodibenzo[6]helicene derivative in 67\% ee. An ultimate "point-to-helical" chirality transfer was observed in the cyclization of enantiopure triynes mediated by Ni(CO)(2)(PPh3)(2) affording (-)-(M)- or (+)-(P)-7,8-bis(p-tolyl)hexahelicen-2-amine in >99\% ee as well as its benzoderivative in >99\% ee. The latter mode of stereocontrol was inefficient for a 2-aminobenzo[6]helicene congener with an embedded five-membered ring. The rac-, (-)-(M)-, and (+)-(P)-7,8-bis(p-tolyl)hexahelicen-2-amines formed Langmuir monolayers at the air water interface featuring practically identical surface pressure vs mean molecular area isotherms. The corresponding Langmuir-Blodgett films on quartz or silicon substrates were characterized by UV vis/ECD spectroscopy and AFM microscopy, respectively.},
  language  = {en}
}