title: Versatile Synthesis of Amino Acid Functional Polymers without Protection Group Chemistry.
abstract: The copolymerization of N-isopropylacrylamide (NiPAm) with aldehyde functional monomers facilitates postpolymerization functionalization with amino acids via reductive amination, negating the need for protecting groups. In reductive amination, the imine formed from the condensation reaction between an amine and an aldehyde is reduced to an amine. In this work, we categorize amino acids into four classes based on the functionality of their side chains (acidic, polar neutral, neutral, and basic) and use their amine groups in condensation reactions with aldehyde functional polymers. The dynamic nature of the imine as well as the versatility of reductive amination to functionalize a polymer with a range of amino acids is highlighted. In this manner, amino acid functional polymers are synthesized without the use of protecting groups with high yields, demonstrating the high functional group tolerance of carbonyl condensation chemistry and the subsequent reduction of the imine. Prior to the reduction of the imine bond, transimination reactions are used to demonstrate dynamic polymers that shuffle from a glycine- to a histidine-functional polymer.
authors.affiliation: Department of Chemical and Biomolecular Engineering and Particulate Fluids Processing Centre, The University of Melbourne , Parkville, VIC 3010, Australia.
authors.forename: Emma R L
authors.initials: ER
authors.lastname: Brisson
authors.affiliation: Department of Chemical and Biomolecular Engineering and Particulate Fluids Processing Centre, The University of Melbourne , Parkville, VIC 3010, Australia.
authors.forename: Zeyun
authors.initials: Z
authors.lastname: Xiao
authors.affiliation: Department of Chemical and Biomolecular Engineering and Particulate Fluids Processing Centre, The University of Melbourne , Parkville, VIC 3010, Australia.
authors.forename: George V
authors.initials: GV
authors.lastname: Franks
authors.affiliation: Department of Chemical and Biomolecular Engineering and Particulate Fluids Processing Centre, The University of Melbourne , Parkville, VIC 3010, Australia.
authors.forename: Luke A
authors.identifier: 0000-0001-7519-977X
authors.initials: LA
authors.lastname: Connal
mesh_terms: D000586:Amination; D000588:Amines / Q000737:chemistry*; D000596:Amino Acids / Q000737:chemistry*; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis*
chemical_list: D000588:Amines; D000596:Amino Acids; D011108:Polymers