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

Abstract

Conjugated polymers have immense potential for their use as semiconducting materials in organic optoelectronic devices. The improvement of synthetic methods for conjugated polymers is important for the practical application of conjugated polymers. For mass production, synthetic methods must be developed by considering the concerns regarding cost and environment. Reduction in the number of synthetic steps is an efficient approach to address these concerns. The utilization of direct CH functionalization is a reasonable strategy in monomer and polymer syntheses, because the prefunctionalization steps for CC bond formation can be eliminated. This review summarizes the recent developments in the efficient syntheses of conjugated polymers as well as their monomers via direct arylation (CH/CX coupling) and cross‐dehydrogenative coupling (CH/CH coupling) reactions.

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.…”

“…DArP, as an emerging subject in the field of OSM synthesis, has been reviewed many times in the past few years. [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] The semiconducting polymers synthesized via DArP are mostly linear homopolymers and alternating copolymers. When homopolymers are prepared using DArP, the monomer has a C-X (X = Cl, Br, I) bond and a C-H bond to proceed a head-to-tail polycondensation (Scheme 4, top).…”

“…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.…”

In Situ Generation of N -Heteroaromatic Polymers: Metal-Free Multicomponent Polymerization for Photopatterning, Morphological Imaging, and Cr(VI) Sensing

“…Generally, the adjustment of electronic structures in polymer materials is achieved by tuning their conjugation length and electron donor-acceptor (D-A) strength. 6 While high-molecular-weight…”

In-Situ Generation of N-Heteroaromatic Polymers: Metal-Free Polymerization and Multiple Functionalities

“…Generally, the adjustment of electronic structures in polymer materials is achieved by tuning their conjugation length and electron donor-acceptor (D-A) strength. 5 While high-molecular-weight conjugated polymers suffer from the problems of synthetic difficulty and low solubility 6 , polymers with D-A building blocks display various advantages such as simple synthesis, ease regulation, structure variation and multiple functionalization. To construct D-A scaffold in polymer frameworks, one of the effective strategies is to introduce heteroatoms (e.g., O, N, and S, etc.)…”