Organocatalyzed synthesis of fluorinated poly(aryl thioethers)

Nathaniel H Park,Gabriel Dos Passos Gomes,Mareva Fevre,Gavin O Jones,James L Hedrick,Igor V Alabugin

doi:10.1038/s41467-017-00186-3

Nathaniel H Park, Gabriel Dos Passos Gomes + Show 4 more

Open Access

https://doi.org/10.1038/s41467-017-00186-3

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Abstract

The preparation of high-performance fluorinated poly(aryl thioethers) has received little attention compared to the corresponding poly(aryl ethers), despite the excellent physical properties displayed by many polysulfides. Herein, we report a highly efficient route to fluorinated poly(aryl thioethers) via an organocatalyzed nucleophilic aromatic substitution of silyl-protected dithiols. This approach requires low catalyst loadings, proceeds rapidly at room temperature, and is effective for many different perfluorinated or highly activated aryl monomers. Computational investigations of the reaction mechanism reveal an unexpected, concerted SNAr mechanism, with the organocatalyst playing a critical, dual-activation role in facilitating the process. Not only does this remarkable reactivity enable rapid access to fluorinated poly(aryl thioethers), but also opens new avenues for the processing, fabrication, and functionalization of fluorinated materials with easy removal of the volatile catalyst and TMSF byproducts.

Highlights

The preparation of high-performance fluorinated poly(aryl thioethers) has received little attention compared to the corresponding poly(aryl ethers), despite the excellent physical properties displayed by many polysulfides
Given the advantages of having perfluoroarene units in polymers, we felt that the preparation of high performance fluorinated poly(aryl thioethers) would be ideally suited for use in coating and device applications
Poly(aryl thioethers) are traditionally prepared via nucleophilic aromatic substitution (SNAr) under conditions that utilize stoichiometric amounts of base, extended reaction times, or in some cases, high temperatures[16,17,18,19,20,21]. These conditions have been utilized for the incorporation of perfluoroaryl-containing monomers into poly(aryl thioethers)[22], they are not ideal, given the propensity of perfluoroarenes to undergo multiple substitutions[3, 23,24,25,26] potentially leading to uncontrolled branching or cross-linking

Summary

Introduction

The preparation of high-performance fluorinated poly(aryl thioethers) has received little attention compared to the corresponding poly(aryl ethers), despite the excellent physical properties displayed by many polysulfides. Poly(aryl thioethers) are traditionally prepared via nucleophilic aromatic substitution (SNAr) under conditions that utilize stoichiometric amounts of base, extended reaction times, or in some cases, high temperatures[16,17,18,19,20,21] These conditions have been utilized for the incorporation of perfluoroaryl-containing monomers into poly(aryl thioethers)[22], they are not ideal, given the propensity of perfluoroarenes to undergo multiple substitutions[3, 23,24,25,26] potentially leading to uncontrolled branching or cross-linking. By heating the reaction with 10 mol % of diisopropylethylamine; results similar to those using DBU could be obtained (entry 11, Table 1)

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