Solid‐Phase Synthesis of Libraries of Triazine Dendrimers and Orthogonal Staining Methods for Tracking Reactions on Resin

Abstract

AbstractReaction tracking is important in solid‐phase synthesis, especially for the preparation of dendrimers. In this study, a pair of orthogonal staining methods involving ninhydrin and Alizarin R was used to monitor the presence of alkyl amines or aryl chlorides, respectively, for tracking a reaction's progress. This staining method was applied to the solid‐phase dendrimer synthesis of a small library of triazine dendrimers that varied in generation from 1 to 3 and with specific ratios of surface groups. Starting with a Rink amide resin, iterative reactions of cyanuric chloride and a linking diamine, aminomethylpiperidine, provided the desired materials. Peripheral dichlorotriazines could be reacted selectively with two different amine nucleophiles to yield a multifunctional surface in a total yield of 81–87 %. The whole preparation process could be accomplished within one week, which dramatically improved the preparation efficiency.