Polymer Constructed Through the Formation of Carbon–Carbon Triple Bonds: Reductive Coupling Polymerization of Bis(benzylic gem-tribromide)s

Abstract

Ethynylene-bridged polymers are currently synthesized by alkyne metathesis polymerization or Pd-catalyzed coupling between diethynylarene and dihaloarene. We report the formation of CC linkages in reductive coupling polymerization of bis(benzylic gem-tribromide)s promoted by Cu/polyamine under mild conditions. The polymer backbone was constructed through cascade formation of (Br)CC(Br) bonds and CC bonds. This protocol provides a new method for synthesis of ethynylene-bridged polymers using monomers without alkynyl groups.

Concurrent Construction of C═C and C≡C Linkages in Organic and Polymerization Reactions

“…In the polymerization of “ 2 – 2 ”-type monomers promoted by Cu(0)/ligand, PMDETA ( N , N , N ′, N ″, N ″-pentamethyldiethylenetriamine), TPMA, or Me 6 TREN results in formation of a trans -CC linkage, respectively . In the polymerization of “ 3 – 3 ”-type monomers, only Me 6 TREN generates a CC linkage . The influence of ligand on the polymerization of a “ 2 – 3 ”-type monomer is first screened.…”

“…To achieve self-coupling of two individual gem -polybromides and complete formation of a CC linkage in the polymerization of 2-X-3 , a two-step polymerization utilized in the polymerization of “ 3 – 3 ”-type monomers is applied . The early polymerization is promoted by TPMA followed by adding Me 6 TREN in the latter polymerization.…”

“…(B) 1 H NMR spectrum of conjugated P(AV- alt -AE) (run 8 in Table ) prepared from monomer 2-Y-3 . (C) 1 H NMR spectrum of PAE prepared by monomer 3-Y-3 . (D) 1 H NMR spectrum of P(AV- co -AE) by copolymerization of 2-Y-2 , 2-Y-3 , and 3-Y-3 (1:1:1) (* CHCl 3 ).…”

“…45 In the polymerization of "3−3"-type monomers, only Me 6 TREN generates a C�C linkage. 51 The influence of ligand on the polymerization of a "2−3"-type monomer is first screened. The monomer 2-X-3 is an ideal candidate due to the good solubility of its polymer.…”

“…Benzylic gem -dibromides and gem -tribromides were prepared by bromination of a substrate with NBS and purified by column chromatography. , The polymerization procedure was reported in pervious publications. , Experimental procedures, synthesis of organic compounds, monomers, and polymers, and their spectral data can be found in the Supporting Information.…”