Patent ID: 6781006
Filing Date: 2004-08-24
Classification: B01J,C07B,C07F

Abstract:
A method for making a chiral catalyst complex, comprising:contacting an asymmetric tetradentate ligand with a BrÃ¸nsted acid, a Co(II) or Cr(II) salt, wherein the acidity of the conjugate acid of the salt is the same as or less than the acidity of the BrÃ¸nsted acid, and an oxidant under conditions effective to allow formation of a chiral catalyst complex of Co(III) or Cr(III) and the ligand, forming a solution of the complex in a water-miscible, protic solvent from which the complex can be precipitated by the addition of water, and adding water to the solution to precipitate at least a portion of the complex.