Direct arylation polycondensation for synthesis of optoelectronic materials

Abstract

Direct arylation polycondensation has been investigated to develop efficient methods for the preparation of conjugated polymer materials for optoelectronic applications. The reaction conditions have been examined to achieve a high molecular weight and minimal structural defects in the recurring structure. Under the optimal conditions, the direct arylation method has several advantages over the conventional method, for example, having few synthetic steps and yielding a high-molecular-weight and high-purity polymer. The obtained high-quality polymer materials show superior performance to those obtained using a conventional method when used in optoelectronic devices such as organic photovoltaics and field effect transistors. Recent developments in C-H/C-H coupling polycondensation are also described.

CH Activation as a Shortcut to Conjugated Polymer Synthesis

“…The Negishi and Kumada–Corriu polymerizations, on the other hand, involve in situ organozinc and organomagnesium intermediates, respectively, and are limited to homopolymer synthesis. Direct (hetero)arylation polymerization ( DHAP or DArP ) and oxidative CH/CH arylation polymerization ( oxi‐DArP ) make accessible the synthesis of both conjugated homo‐ and copolymers by means of palladium‐catalyzed CH activation, thereby avoiding many of the setbacks inherent to other polymerization techniques …”

Advances in applying C–H functionalization and naturally sourced building blocks in organic semiconductor synthesis

“…Direct arylation and oxidative C-H/C-H coupling are the two C-H activation involved synthetic routes for OSMs as green alternatives to the conventional synthetic methods, such as Suzuki and Stille couplings, due to their high atom economy (Scheme 2). [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] For instance, the atom economy of a Suzuki coupling shown in Scheme 1a is calculated to be 60%. If direct arylation and oxidative C-H/C-H coupling were used instead to synthesize the same organic semiconducting product in Scheme 1a, respectively, then the values of atom economy would be 80% for direct arylation and 99% for oxidative C-H/C-H coupling.…”

“…Many scientific endeavors have been made to improve the environmental impact of OSMs, including shortening the synthetic routes by adopting C-H functionalization, applying green solvents, replacing the toxic and scarce metal catalysts with earth abundant (first row) transition metal catalysts, reducing the energy consumption by performing the synthesis under ambient conditions, as well as utilizing naturally sourced building blocks. [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] This review highlights the progress on enhancing the environmental friendliness of synthetic protocols, consisting of synthetic routes, reagents, reaction conditions, and building blocks of OSMs, made in the past four years to facilitate the large-scale production and commercialization of OSMs. Specifically, the purification and processing of OSMs are outside the scope of this review.…”

Step‐Economical Synthesis of Conjugated Polymer Materials Composed of Three Components: Donor, Acceptor, and π Units

“…To realize the practical applications of conjugated polymers, efficient synthetic methods that take into account the concerns regarding cost and environment must be developed. [ 7 – 11 ] Reduction in the number of synthetic steps is an effective approach to address these concerns. Osedach et al.…”