title: Efficient enantioselective synthesis of condensed and aromatic-ring-substituted tyrosine derivatives.
abstract: An efficient access to both condensed and conjugated tyrosine analogues of high enantiomeric purity is described. Novel ring-substituted tyrosines were synthesized by Suzuki cross couplings of appropriately protected l-3-iodotyrosine with a series of activated and deactivated boronic acid derivatives to achieve the target compounds in high yields. d- and l-4-hydroxy-1-naphthylalanines were readily prepared from the corresponding alpha-enamide in two different approaches, by asymmetric hydrogenation as well as by unselective hydrogenation and enzymatic resolution of the racemic mixture.
authors.affiliation: Lehrstuhl II für Organische Chemie, Department Chemie, Technische Universität München, Lichtenbergstrasse 4, Garching D-85747, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Knör
authors.forename: Burkhardt
authors.initials: B
authors.lastname: Laufer
authors.forename: Horst
authors.initials: H
authors.lastname: Kessler
mesh_terms: D002384:Catalysis; D009682:Magnetic Resonance Spectroscopy; D007470:Monoiodotyrosine / Q000737:chemistry; D013237:Stereoisomerism; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis*
chemical_list: D014443:Tyrosine; D007470:Monoiodotyrosine