ROMP Copolymers for Orthogonal Click Functionalizations

Abstract

ABSTRACT:The ring-opening metathesis polymerization using ruthenium carbene initiators developed by Grubbs et al. is one of the most functional group tolerant living polymerization methods known. One of the most used postpolymerization functionalization methods used today is the copper-catalyzed 1,3-dipolar cycloaddition between alkynes and organic azides. Organic azides are, however, not tolerated by ruthenium carbene initiators, and nonprotected alkynes have been shown to slow down the propagation reaction or react with the propagating species leading to broad molecular weight distributions. Here we report the copolymer synthesis of three orthogonally functionalizable monomers: one carrying an activated pentafluorophenyl ester, one a maleimide unit, and a third one a trialkylsilyl-protected alkyne. From these monomers, statistical terpolymers as well as diblock copolymers were synthesized with different molecular weights and monomer compositions or block ratios, respectively. Excellent control over molecular weight and molecular weight distribution could be achieved using Grubbs' firstgeneration ruthenium carbene initiator. Herein we present the synthesis and orthogonal triple postpolymerization functionalization of these copolymers.

Activated Ester Containing Polymers: Opportunities and Challenges for the Design of Functional Macromolecules

“…Orthogonally clickable statistical terpolymers and diblock copolymers featuring PFP-ester and protected alkyne side groups were obtained using PFPNorb as one of the monomers. 289 …”

“…A three-step PPM with benzyl mercaptan, hexylamines, and piperonyl azide, respectively, led to multifunctional polymer (Scheme 49). 289 Even incorporating two different activated ester monomers within a polymer chain with disparate reactivities allows for selective aminolysis by sequential addition of amines. Exploring the reactivity difference of PFP4VB and PFPMA, Theato et al sequentially modified individual repeat units of statistical and block copolymers of PFP4VP and PFPMA with aromatic and aliphatic amines selectively.…”

Quinoline-functionalized norbornene for fluorescence recognition of metal ions

“…With commercial available 5-norbornene-endo-2,3-dicarboxylic anhydride and 8-aminoquinoline as starting materials, we firstly prepared the two key precursors exo-norbornene-2,3-dicarboximide (2) and 2-chloro-N-(quinol-8-yl)-acetamide (3) according to the literature methods [49]. The quinoline-appended norbornene monomer 1 was then easily obtained by condensation of 2 and 3 with K 2 CO 3 /TBAB (tetrabutyl ammonium bromide) as the catalysts in CH 3 CN solution.…”

Ring-opening reactions of backbone epoxidized polyoxanorbornene

“…To date, the most widely used click reactions applied in synthetic polymer chemistry are Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC), Diels-Alder cycloaddition, thiol-ene (or thiol-yne), nitroxide radical coupling (NRC), and amine-or thiol-epoxy reactions [1,[13][14][15][16][17]. ROMP-click combinations allowed for the synthesis of a variety of polymers via efficient polymer-polymer conjugations, leading to block, graft, and star polymers [18][19][20][21][22][23][24][25][26][27][28] and for the post-functionalization of polymers [29][30][31][32]. Although ROMP backbone could be envisioned a source of accessing different functionalities such as analogous small organic compounds possessing double bond, most of the post-functionalization of ROMP through A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 3 click reactions have been taken place on the side chains.…”