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 d eveloped. Starting from Merrifield resin, the new N-butyl-N-methylpolystyre ne-hydrazine linker is prepared in three steps. Polymer-supported hydrazone s, readily prepared from aldehydes and the hydrazine resin, react with alky l- and arylorganolithium reagents under 1,2-addition to the C-N double bond to afford the corresponding hydrazines. Release from solid support was ach ieved by reductive N-N bond cleavage using the borane-tetrahydrofuran compl ex. The resulting a-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).