223596-84-7Relevant articles and documents
Synthesis of aromatic triynes as precursors to helicene derivatives
Stara, Irena G.,Kollarovic, Adrian,Teply, Filip,Stary, Ivo,Saman, David,Fiedler, Pavel
, p. 577 - 609 (2007/10/03)
A general and versatile synthetic approach to a broad series of aromatic triynes as precursors to helicene derivatives has been developed. Employing a set of simple tools, triynes comprising the (phenylethynyl)benzene, 1-(phenylethynyl)naphthalene, and 1-(1-naphthylethynyl)-naphthalene moiety have been prepared in good to excellent yields throughout the whole reaction sequence. The methodology allows constructing various types of a junction between the central diarylacetylene moiety and the attached acetylene units to get the target triynes of general formula R-C≡C-CH2-X-CH2-Ar-C≡C-Ar-CH 2-X-CH2-C≡C-R or R-C≡C-CH2CH2-Ar-C=C-Ar-CH2CH 2-C≡C-R (R = H, CH3, TMS, or TIPS; X = O, NTs, or C(CO2CH3)2; Ar/Ar = 2-phenylene or 2-naphthylene).
Transition metal catalysed synthesis of tetrahydro derivatives of [5]-, [6]- and [7] helicene
Stara, Irena G.,Stary, Ivo,Kollarovic, Adrian,Teply, Filip,Vyskocil, Stepan,Saman, David
, p. 1993 - 1996 (2007/10/03)
Tetrahydro analogues of [5]-, [6]- and [7] helicene have been easily prepared by intramolecular [2+2+2] cycloisomerization of appropriate triynes under CpCo(CO)2/PPh3 or Ni(cod)2/PPh3 catalysis. This nonphotochemical methodology allows enantioselective synthesis of a helical skeleton employing the Ni(cod)2/(S)-(-)-MOP catalytic system. On reaction with DDQ, tetrahydro[5]helicene was transformed to [5]helicene.
