New Simple Polymeric Supports with Hydrazone Linkers for Solid-Phase Synthesis of Ketones and Primary Amines

ABSTRACT The preparation of new solid supports with hydrazine anchoring groups and their application to solid-phase synthesis of ketones and primary amines are described. The supports were used for immobilization of ketones, 4-TERT-butylcyclohexanone, pentan-3-one, acetone, N-methylpiperidone, N-benzylpiperidone, and tropinone in the form of their hydrazones. The polymer-supported hydrazones were subjected to deprotonation/alkylation procedure (LDA/RX) once or twice. The resulting alkylated products were cleaved off the solid support on treatment with trifluoroacetic acid in tetrahydrofuran providing α-alkylated or α,α′-bisalkylated ketones or were subjected to reductive cleavage with borane in tetrahydrofuran to give β-alkylated or β,β′-bisalkylated primary amines.