Polymers Derived from Unsaturated Carbodiimides

Vinyl polymers 26 bearing pendant carbodiimide groups, are obtained from N-(p- or o-vinylphenyl)-N -alkylcarbodiimides.  

Polymers with pendant carbodiimide groups 27 are also synthesized from crossUnked polystyrene. In this synthetic route crossUnked polystyrene beads are chloromethylated and converted to the amines. Reaction with isopropyl isocyanate gives the corresponding ureas, which are treated with tosyl chloride and triethylamine to produce the crossUnked polycarbodiimides. This polymer is used in the polymer supported Moffatt oxidation of alcohols into aldehydes or ketones using benzene/DMSO.  

reaction of the aminomethyl polystyrene with cyclohexylisocyanate affords a polymer bound urea, which is converted into the carbodiimide using Ph3PBr2. Reaction of the polycarbodiimide with methanol affords an 0-alkylisourea which is used in the 0-alkylation of carboxylic acids.  

When aminomethyl polystyrene is reacted with dialkylcarbodiimides, the corresponding polyguanidines are obtained which exhibit high selectivity towards Au(CN)2 ions. Also, reaction of chloromethyl polystyrene with EDC affords the polymeric EDC hydrochloride 28. This polymer is used in the coupling of amino acids with carboxylic acids (yield 72-100 %).  

PEDC is also applied to esterify carboxylic acids with N-hydroxysuccinimide or penta-fluorophenol. Also, reaction of PEDC with heterocyclic carboxylic acids affords the corresponding anhydrides, which are converted with aniline derivatives into hetero-cyclic carboxamides.  

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For more examples of polymers derived from unsaturated carbodiimides see Section 12.4. 

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