Robin

The application of mechanical force to a material can lead to the generation of electric charge; piezoelectricity. For the first time, this effect has been harnessed and applied to radical reactions under ball-milling conditions, this Concept briefly describes the first appearances of this ground-breaking technique in the literature.

Abstract

Recent research endeavors have established that the mechanochemical activation of piezoelectric materials can open new avenues in redox chemistry. Impact forces, such as those imparted by a ball mill, have been shown to transform piezoelectric materials such as barium titanate (BaTiO₃) into a highly polarized state, which can then donate an electron to a suitable oxidant and receive an electron from a suitable reductant, mimicking established photoredox catalytic cycles. Proof-of-concept studies have elucidated that mechanoredox chemistry holds great potential in sustainable and efficient radical-based synthesis.

Synlett
DOI: 10.1055/a-1499-8679

Recently, development of general synthetic routes to unnatural α-amino acids has gained significant momentum, driven by the high demand for such building blocks in fundamental research within molecular and structural biology, as well as for development of new pharmaceuticals. Herein, we highlight the recent progress in employing photoredox-mediated synthetic methods for accessing unnatural α-amino acids with a focus on various decarboxylative radical-based strategies.
[...]

Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

Article in Thieme eJournals:
Table of contents  |  Abstract  |  Full text

A metal-free photoredox catalyzed controlled alternating terpolymerization of perfluorinated vinyl ethers has been established, enabling the on-demand synthesis of various fluorinated terpolymers driven by light. This method offers a versatile and convenient platform to tailor fluoropolymers, which facilitates the preparation of novel block copolymers and engineering of high-performance solid terpolymer electrolytes.

Abstract

Polymerizations of perfluorinated vinyl ethers (PFVEs) provide an important category of fluoropolymers that have received considerable interests in applications. In this work, we report the development of an organocatalyzed controlled radical alternating terpolymerization of PFVEs and vinyl ethers (VEs) under visible-light irradiation. This method not only enables the synthesis of a broad scope of fluorinated terpolymers of low dispersities and high chain-end fidelity, facilitating tuning the chemical compositions by rationally choosing the type and/or ratio of comonomers, but also allows temporal control of chain-growth, as well as the preparation of a variety of novel fluorinated block copolymers. To showcase the versatility of this method, fluorinated alternating terpolymers have been synthesized and customized to simultaneously display a variety of desirable properties for solid polymer electrolyte design, creating new opportunities in high-performance energy storage devices.

Synlett
DOI: 10.1055/s-0040-1706042

Reduction-and-oxidation (redox) reactions are one of the most utilized approaches for the synthesis of value-added compounds. With the growing awareness of green chemistry, researchers have searched for new and sustainable pathways for performing redox reactions. From this, a new field has gained tremendous attention, namely photoredox catalysis. Here, molecules can be easily oxidized or reduced with the use of one of Nature’s biggest resources: visible light. This tutorial paper gives the basics of photoredox catalysis along with limited examples to encourage further research in this blooming research area.1 Introduction2 Redox Chemistry3 Photochemistry3.1 Laws of Photochemistry3.2 Principles3.3 Examples4 Photoredox Catalysis4.1 General Principles4.2 Classification of Redox Processes4.3 Other Mechanistic Considerations4.4 Stern–Volmer Plots4.5 Photophysical Properties4.6 Redox Potentials5 Photocatalysts5.1 Metal-Based Photocatalysts5.2 Organic Dyes5.3 Semiconductors6 Dual Catalysis7 Conclusions
[...]

Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

Article in Thieme eJournals:
Table of contents  |  Abstract  |  Full text