Functionalized Polymers Using Protected Thiols

Abstract

A process for the preparation of functional molecules using the thiol-ene coupling reaction and a process for the preparation of protected functional thiols, specifically thioesters is provided. The methods may be used to make functional polymers and other molecules. The method of making a functionalized polymer using a thiol-ene reaction comprises: providing a functionalized thioester having the following formula: wherein R is a functional group and COR′ is a protecting group; cleaving the functionalized thioester, forming a functional thiol and an acyl group; providing a polymer having a pendant vinyl group; and reacting the polymer with the functional thiol whereby a functionalized polymer is formed, wherein the functional thiol is not isolated prior to reacting with the polymer.

We claim: 
     
         1 . A functionalized thioester made by a method of preparing a functionalized thioester comprising:
 (a) reacting a nucleophilic starting material having a desired functional group with a nonsymmetrical bifunctional linker molecule, forming a functionalized intermediate; and (b) reacting the functionalized intermediate with a thiol acid to form a functionalized thioester.   
     
     
         2 . A functionalized thioester having the following formula: 
       
         
           
           
               
               
           
         
         wherein R is a functional group and COR′ is a protecting group that is readily cleaved to provide a functional thiol that may be used without isolation to perform thiol-ene coupling. 
       
     
     
         3 . The functionalized thioester of  claim 2 , wherein the protecting group is an acetyl or benzoyl group. 
     
     
         4 . The functionalized thioester of  claim 2 , wherein the functional group is selected from the group consisting of: amino acid, peptide, polypeptide, nucleic acid, lipid, carbohydrate, carbazole, benzoate, phenol, pyridine, cyanobiphenyl, perfluorocarbon, polyethylene oxide (PEO) and polypropyleneoxide (PPO) groups