Enantioselective Synthesis of [7]Helicene: Dramatic Effects of Olefin Additives and Aromatic Solvents in Asymmetric Olefin Metathesis
作者:Alain Grandbois、Shawn K. Collins
DOI:10.1002/chem.200801033
日期:2008.10.20
The asymmetric synthesis of [7]helicene was accomplished in good ee (80%) by kinetic resolution by means of asymmetric olefinmetathesis. Three key factors contributed to the success of the kinetic resolution: the use of new Ru-based olefinmetathesis catalysts bearing C1-symmetric N-heterocyclic carbene ligands, simple olefins as additives to control the nature of the propagating alkylidene and hexafluorobenzene