@Article{AngewChemIntlEd_42_3162, author = {C. Herse and D. Bas and F.C. Krebs and T. B{\"u}rgi and J. Weber and T. Wesolowski and B.W. Laursen and J. Lacour}, title = {{A Highly Configurationally Stable [4]Heterohelicenium Cation}}, journal= {Angew. Chem. Intl. Ed.}, ISSN = {1433-7851}, volume= {42}, number= {27}, pages = {3162-3166}, url = {http://www3.interscience.wiley.com/cgi-bin/abstract/104545537/START}, doi= {10.1002/anie.200351443}, keywords= {asymmetric synthesis;carbenium ions;chiral resolution;circular dichroism;helicenes}, abstract = {{A [4](hetero)helicenium cation was resolved using the hexacoordinated phosphorus-containing binphat anion (see picture: N, blue; O, red; C, gray). Its absolute configuration was determined by vibrational circular dichroism spectroscopy. The barrier of interconversion of its enantiomers is higher than that of [6]helicene.}}, year = {2003} }