Azide/Alkyne-Click-Reactions on Amino Resin Materials: An LC-ESI-TOF Analysis

This article describes the reaction of amino resins with functional molecules using the azide/alkyne-click-reaction, opening a simple chemical modification of amino resins under aqueous conditions. Alkyne-modified melamine-formaldehyde resins resins are prepared via a direct cocondensation approach using propargylic alcohol (21.6-86.3 mmol) as additive. Subsequently, alkyne-modified mono-, bi-, and trinuclear melamine-species are identified via LC-ESI-TOF methods proving the covalent incorporation of alkyne-moieties in amounts of up to 3.9 mol %. Subsequent modification of the alkyne-modified resins was accomplished by reaction of functional azides (octyl azide (1), (azidomethyl)benzene (2), 1-(6-azidohexyl) thymine (3), and 4-azido-N-(2,2,6,6-tetramethylpiperidin-4-yl)benzamide (4)) with Cu(I)Br and DIPEA as a base. The formation of triazolyl-modified ME-resins was proven by LC-ESI-TOF methods, indicating the successful covalent modification of the amino resin with the azides 1-4. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4855-4866, 2010