Enantioselective catalysis in fluorinated media - Synthesis and propertiesof chiral perfluoroalkylated (salen)manganese complexes

Chiral (salen)manganese complexes, which are selectively soluble in perfluo rocarbons, were synthesized and tested as epoxidation catalysts in fluorous -organic two-phase systems. The immiscibility of the perfluorocarbons with regular organic solvents allowed a quick and effective separation of the ca talyst from the products. These unprecedented perfluoroalkylated salen comp lexes were found to be efficient and chemoselective catalysts in the presen ce of several oxygen donors. but enantioselectivities were generally poor. An interesting exception to this behaviour was observed in the asymmetric e poxidation of indene that provides indene oxide with 70-92% enantiomeric ex cess.