ENANTIOSELECTIVE SYNTHESIS OF A STERICALLY HINDERED AMINE

摘要

Compounds of the formula I wherein R is phenyl, or phenyl substituted by CI, Br, C1-C4alkyl or CF3; Ri is H or methyl or ethyl; R2 is H or methyl or acyl; R3 is H or methyl; R'4 is -CH3 or =CH2; may be obtained in high enantiopurity by hydrogenation of a compound of the formula II wherein R and R3 are as in formula I; A is acyl; and R4 is -CH3 or =CH2; in the presence of a chiral Rhodium or Ruthenium catalyst. Residues R-i as methyl or ethyl and/or R2 as H or methyl may subsequently be introduced without racemization by deacylation and optional alkylation.