Synthesis of novel chiral lipophilic pyridyl-containing beta-amino alcoholligands and enantioselective hydrolysis of alpha-amino acid esters by chiral metallomicelles

Seven novel chiral lipophilic pyridyl-containing beta-amino alcohol ligands have been synthesized by coupling of 6-alkoxymethyl-2-chloromethylpyridine 3 with the corresponding chiral beta-amino alcohols or L-cysteine. Their m etal ion complexes have been investigated as catalysts for the enantioselec tive hydrolysis of N-protected alpha-amino acid esters in aqueous comicella r solution. The results indicate that the hydrophobic interactions between substrate and metallocatalyst, the rigidity of the ligand, the hydroxyl gro up of the ligand acting as a nucleophile for the transacylation process, an d the micellar microenvironment are important factors for the activity and enantioselectivity. Large rate accelerations (up to three orders of magnitu de) and moderate enantioselectivities (up to 7.81 (k(R)/k(S))) employing 4a -Cu2+ have been observed. (C) 1999 Elsevier Science Ltd. All rights reserve d.