Two-fold amino acid-based chiral aminophosphine–oxazolines and use in asymmetric allylic alkylation

Chiral aminophosphine–oxazoline ligands derived from two different amino acids (tetrahydroisoquinoline carboxylic acid and proline) have been synthesized and examined as chiral auxiliaries in asymmetric allylic alkylation of three substrates. Stereoisomers 1a and 2a are providing the highest enantioselectivities (up to 94% ee) in the allylation of diphenylpropenyl acetate.