title: Enantioselective Synthesis of Diamino Dicarboxylic Acids.
abstract: The preparation of alkyl diamino dicarboxylic acids with high optical purity (100% ee, >98.5% de) and high yields based on asymmetric catalytic hydrogenation is described. The required prochiral precursors are prepared from dialdehydes and Z-, Boc-, and acetyl-protected phosphonoglycines. Aqueous solutions of glyoxal, succinic dialdehyde, and glutaric dialdehyde were used to prepare the diunsaturated precursors for 2,5-diaminoadipic acid (DAA), 2,7-diaminosuberic acid (DAS), and 2,8-diaminoazelaic acid (DAZ). Z-Protected dimethyl esters of DAA, DAS, and DAZ were obtained by hydrogenation of the corresponding prochiral starting materials with [(COD)Rh(S,S)-Et-DuPHOS]OTf.
authors.affiliation: Topcro Pharma Research GmbH, St. Peter Strasse 25, A-4020 Linz, Austria; Hafslund Nycomed Pharma AG, St. Peter Strasse 25, A-4020 Linz, Austria; and Nycomed Austria AG, St. Peter Strasse 25, A 4020 Linz, Austria.
authors.forename: Johann
authors.initials: J
authors.lastname: Hiebl
authors.forename: Hermann
authors.initials: H
authors.lastname: Kollmann
authors.forename: Franz
authors.initials: F
authors.lastname: Rovenszky
authors.forename: Karin
authors.initials: K
authors.lastname: Winkler