Thiol-Michael coupling and ring-opening metathesis polymerization: facile access to functional exo-7-oxanorbornene dendron macromonomers

Thiol‐Michael Coupling and ROMP: Facile Access to Functional exo‐7‐Oxanorbornene Dendron Macromonomers Nucleophile‐mediated thiol‐Michael coupling is employed to prepare a small library of functional thioether‐based dendron monomers from novel di‐ and tetra‐acrylate functional ring‐opening metathesis polymerization (ROMP)‐active exo‐7‐oxanorbornene‐based monomers. The ROMP (co)polymerization of these novel monomers is evaluated with Grubbs 1st and 3rd generation initators. This paper describes the synthesis of the 2‐ and 4‐functional acrylic exo‐7‐oxanorbornene species 2‐((2‐((3aR,7aS)‐1,3‐dioxo‐1,3,3a,4,7,7a‐hexahydro‐2H‐4,7‐epoxyisoindol‐2‐yl)ethoxy) carbonyl)‐2‐methylpropane‐1,3‐diyl diacrylate and (((2‐((2‐((3aR,7aS)‐1,3‐dioxo‐1,3,3a,4,7,7a‐hexahydro‐2H‐4,7‐epoxyisoindol‐2‐yl)ethoxy) carbonyl)‐2‐methylpropane‐1,3‐diyl)bis(oxy))bis(carbonyl))bis(2‐methylpropane‐2,1,3‐triyl) tetraacrylate, and their use as common precursors for the preparation of a small library of dendronized thioether adducts via nucleophile‐mediated thiol‐Michael coupling chemistry. We subsequently demonstrate that the dendronized monomers can be (co)polymerized via ring‐opening metathesis polymerization employing Grubbs'‐type Ru‐based initiators to give novel functional dendronized (co)polymers of predictable molecular weights and acceptable dispersities (ĐM = M‾ w/ M‾ n). © 2013 Society of Chemical Industry