511519-40-7Relevant academic research and scientific papers
A versatile synthesis of functionalized pentahelicenes
Songis, Olivier,Misek, Jiri,Schmid, Markus B.,Kollarovic, Adrian,Stara, Irena G.,Saman, David,Cisarova, Ivana,Stary, Ivo
experimental part, p. 6889 - 6899 (2010/11/18)
A general synthetic methodology for the preparation of functionalized (hetero)helicenes has been developed. It employs the sequence of a double propargyl organometallics (Li, Mg, Ga/In) addition to a tolan-2,2′- dialdehyde-type intermediate, a cobalt-catalyzed/cobalt-mediated [2 + 2 + 2] cycloisomerization of a triyne intermediate, and a double silica gel-assisted acetic acid elimination to receive pentahelicene, 1,14-diazapentahelicene, and 3,12-dichloro-, 3,12-dichloro-7-trimethylsilyl-, and 3,12-di-tert- butylpentahelicene. 3,12-Dichloropentahelicene undergoes a Suzuki-Miyaura coupling with aryl boronic acids (or ester) under palladium catalysis to afford 3,12-diarylpentahelicenes.
