Nonstoichiometric Direct Arylation Polymerization of Octafluorobiphenyl with 2,7‐Diiodofluorene for Regulating CH Terminals of π‐Conjugated Polymer

Abstract

Nonstoichiometric direct arylation polycondensation of 2,2′,3,3′,5,5′,6,6′‐octafluorobiphenyl with excess of 2,7‐diiodo‐9,9‐dioctyl‐9H‐fluorene is demonstrated. Pd/Ag dual‐catalyst system under water/2‐methyltetrahydrofuran biphasic conditions enables direct arylation under mild conditions and promotes the intramolecular transfer of a Pd catalyst walking through the fluorene moiety. The nonstoichiometric direct arylation polycondensation under the optimized reaction conditions produces the corresponding π‐conjugated polymer with a high molecular weight and terminal octafluorobiphenyl units at both ends.

Direct synthesis of π-conjugated polymers with bromoaryl groups in side chains via a chemoselective intramolecular catalyst transfer system

“…Such catalyst transfer systems are utilized for synthesizing high-molecular-weight polymers via single-phase polycondensations under nonstoichiometric conditions. 12,13,15–18 Similarly to the previous work, P1′′ , whose M SEC n = 11 000 ( M w / M n = 1.97) (Fig. S20†) was significantly higher than the theoretical one ( M theory n = 2200, calculated based on Carothers/Flory theory 19–21 ), was obtained even at a nonstoichiometric monomer feed ratio.…”

“…Similarly to P1′′ , an intramolecular Pd catalyst transfer system walking on 4 after the first cross-coupling reaction with 1 might allow nonstoichiometric polycondensation reactions. 12,13,15–18…”