Novel Thiophene–Phenylene–Thiophene Fused Bislactam-Based Donor–Acceptor Type Conjugate Polymers: Synthesis by Direct Arylation and Properties

Technological Innovations in Photochemistry for Organic Synthesis: Flow Chemistry, High-Throughput Experimentation, Scale-up, and Photoelectrochemistry

Photoinduced chemical transformations have received in recent years a tremendous amount of attention, providing a plethora of opportunities to synthetic organic chemists. However, performing a photochemical transformation can be quite a challenge because of various issues related to the delivery of photons. These challenges have barred the widespread adoption of photochemical steps in the chemical industry. However, in the past decade, several technological innovations have led to more reproducible, selective, and scalable photoinduced reactions. Herein, we provide a comprehensive overview of these exciting technological advances, including flow chemistry, high-throughput experimentation, reactor design and scale-up, and the combination of photo- and electro-chemistry.

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

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.

Thiophene-embedded conjugated microporous polymers for photocatalysis

“Bottom-up” embedding of thiophene derivatives into CMPs for highly efficient heterogeneous photocatalysis is reported.

Synthesis of azuleno[2,1-b]thiophenes by cycloaddition of azulenylalkynes with elemental sulfur and their structural, optical and electrochemical properties

The reaction of several azulenylalkynes having an aryl substituent with elemental sulfur afforded the corresponding azuleno[2,1-b]thiophenes in good yields.

Synthesis and Field-Effect Transistor Application of π-Extended Lactam-Fused Conjugated Oligomers obtained by Tandem Direct Arylation

Five π-extended lactam-fused conjugated oligomers (5FO, 5FS, 4FPO, 4FPS, and R-4FPO) were synthesized by the tandem direct arylation. The intermolecular oxidative direct arylation was applied in the second step. These conjugated oligomers had fine-tuned FMO energies predictable by the theoretical calculation and excellent thermal stabilities. 4FPO and 4FPS bearing tetrafluoropyridine exhibited lower LUMO energy levels (-3.20 eV and -3.39 eV, respectively) compared with others. Based on the X-ray crystallography, 4FPO was found to have a herringbone crystal packing and a considerably large electron transfer integral value (137 meV). 4FPO-based bottom-gate, bottom-contact FET device demonstrated an electron mobility of 5.2×10^-3  cm²  V^-1  s^-1 as a result of an edge-on alignment on the SiO₂ substrate.

Direct Arylation Strategies in the Synthesis of π-Extended Monomers for Organic Polymeric Solar Cells

π-conjugated macromolecules for organic polymeric solar cells can be rationally engineered at the molecular level in order to tune the optical, electrochemical and solid-state morphology characteristics, and thus to address requirements for the efficient solid state device implementation. The synthetic accessibility of monomers and polymers required for the device is getting increasing attention. Direct arylation reactions for the production of the π-extended scaffolds are gaining importance, bearing clear advantages over traditional carbon-carbon forming methodologies. Although their use in the final polymerization step is already established, there is a need for improving synthetic accessibility to implement them also in the monomer synthesis. In this review, we discuss recent examples highlighting this useful strategy.

Expedited access to thieno[3,2-c]quinolin-4(5H)-ones and benzo[h]-1,6-naphthyridin-5(6H)-ones via a continuous flow photocyclization method

A single-step continuous flow method has been developed that gives expedited access to complex heterocycles via an intramolecular photochemical cyclization. Herein we report the first examples of the photochemically-induced generation of thieno[3,2-c]quinolin-4(5H)-ones, 16 examples, and benzo[h]-1,6-naphthyridin-5(6H)-ones, 6 examples. Overall, the continuous flow method provides access to complex heterocycles in two steps from commercially available starting materials in good yields and with greater atom efficiency than traditional batch reactions.

Amide-bridged terphenyl and dithienylbenzene units for semiconducting polymers

Semiconducting polymers with new “electron-neutral” amide-bridged building units were designed, synthesized, and studied as materials for organic devices.

Stereoisomers of an azine-linked donor–acceptor conjugated polymer: the impact of molecular conformation on electrical performance

We herein report the synthesis of a pair of azine linked donor–acceptor type conjugated polymers by the use of palladium(ii)-based direct arylation.

Donor–acceptor conjugated polymers based on multifused ladder-type arenes for organic solar cells

In this review, we summarize the recent development of the multifused ladder-type conjugated building blocks for making donor–acceptor conjugated copolymers.

Third-order nonlinear optical properties of 3,4-ethylenedioxythiophene copolymers with chalcogenadiazole acceptors

3,4-Ethylenedioxythiophene–chalcogenadiazole copolymers with a low optical limiting threshold have been synthesized via direct arylation.

D–A copolymers containing lactam moieties for polymer solar cells

D–A copolymersP1andP2containing a new lactam acceptor unit BDTP and BDT or selenophene as a donor unit gave PCEs of 5.05% and 6.76%, respectively.

Pentacyclic aromatic bislactam-based conjugated polymers: constructed by Beckmann rearrangement and application in organic field-effect transistor

Based on the pentacyclic aromatic bislactam constructed through the Beckmann rearrangement, two conjugated polymers were developed, showing high field-effect transistor performance.