32089-81-9Relevant articles and documents
Ring opening with kinetic resolution of azlactones by Ti-TADDOLates
Gottwald, Konstanze,Seebach, Dieter
, p. 723 - 738 (2007/10/03)
The kinetic resolution of azlactones by the Lewis, acid-mediated transfer of an isopropoxide ligand from the chiral ligand sphere of Ti- TADDOLate is described. The reactions proceed with in-situ racemization of the starting material to afford highly enantiomerically enriched N-benzoyl- amino acid isopropylesters (er > 95:5 after recrystallization). The absolute configuration of the major enantiomer of N-benzoyl-phenylalanine isopropyl ester and its analogs with other aromatic substituents was shown to be (S)- (+) when the (R,R)-Ti-TADDOLate was employed. Only benzyl-substituted azlactones can be opened enantioselectively by the method described here.