A reusable enantioselective catalytic system for the Kharasch-Sosnovsky allylic oxidation of alkenes based on a ditopic azabis(oxazoline) ligand

作者：Aldea Luis; Delso Ignacio; Hager Markus; Glos Martin; Garcia Jose I^*; Mayoral Jose A; Reiser Oliver

来源：Tetrahedron, 2012, 68(17): 3417-3422.

DOI：10.1016/j.tet.2011.10.009

• Copper catalysis
• Bis(oxazoline) ligands
• Allylic oxidation
• Kharasch-Sosnovsky oxidation
• Supported catalysts

An easily recoverable and reusable enantioselective catalytic system based on the self-assembly of a coordination polymer through the use of a chiral ditopic ligand, is described for the allylic oxidation of cycloalkenes with tert-butyl perbenzoate. Upon addition of the substrates and a coordinating solvent (acetone or acetonitrile) the coordination polymer disassembles, allowing the catalysis to take place in homogeneous phase. After completion of the reaction, the catalyst reassembles as a coordination polymer upon solvent evaporation and addition of hexane, and is recovered as an insoluble solid. This way, good enantioselectivities and yields are obtained in seven consecutive operation cycles.

• 出版日期2012-4-29