Asymmetric synthesis of alpha-branched primary amines on solid support via novel hydrazine resins.
[reaction: see text]. Two novel chiral hydrazine resins for asymmetric solid-phase synthesis have been developed. The enantiopure beta-methoxyamino auxiliaries, derived from trans-4-hydroxy-(S)-proline and (R)-leucine, were attached to Merrifield resin and transformed into their corresponding hydrazines. Immobilization of various aldehydes, followed by 1,2-addition of organolithium reagents to the resulting enantiopure hydrazones and reductive cleavage from the solid support, furnished alpha-branched amines, which were isolated as their corresponding amides in good overall yields and enantiomeric excesses of up to 86%.
Enders
D
D
Institut für Organische Chemie der Rheinisch-Westfälischen Technischen Hochschule Aachen, Professor-Pirlet-Strasse 1, D-52074 Aachen, Germany. enders@rwth-aachen.de
Kirchhoff
J H
JH
Köbberling
J
J
Peiffer
T H
TH
D000588:Amines / Q000138:chemical synthesis*; D006834:Hydrazines / Q000737:chemistry*; D007930:Leucine / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D010452:Peptide Biosynthesis; D011392:Proline / Q000737:chemistry; D012116:Resins, Plant / Q000737:chemistry*
D000588:Amines; D006834:Hydrazines; D012116:Resins, Plant; C029424:hydrazine; D011392:Proline; D007930:Leucine