A Novel Hydrazine Linker Resin and Its Application for the Solid-Phase Synthesis of alpha-Branched Primary Amines.
A novel hydrazine linker resin for solid-phase organic synthesis has been developed. Starting from Merrifield resin, the new N-butyl-N-methylpolystyrene-hydrazine linker is prepared in three steps. Polymer-supported hydrazones, readily prepared from aldehydes and the hydrazine resin, react with alkyl- and arylorganolithium reagents under 1,2-addition to the C-N double bond to afford the corresponding hydrazines. Release from solid support was achieved by reductive N-N bond cleavage using the borane-tetrahydrofuran complex. The resulting alpha-branched primary amines were protected as their amides or carbamates, respectively, and, after purification, were obtained in good overall yields and in high purity (12 examples).
Kirchhoff
JH
RWTH Aachen, Institut für Organische Chemie, Professor-Pirlet-Strasse 1, 52074 Aachen, Germany.
Bräse
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