A redox-neutral
C2-selective methylation of heterocyclic N-oxides
with sulfonium ylides is described herein. This
report presents unprecedented findings for the utility of sulfonium
ylides as the methylation source of N-heterocycles
beyond the Corey–Chaykovsky reaction. Intriguingly, pyrrolidine
plays a significant role in minimizing the reductive C2-methylation
process. This method is characterized by its mild conditions, simplicity,
and excellent site selectivity. The applicability of the developed
protocol is showcased by the late-stage methylation and sequential
transformations of complex drug molecules.
Most photodetectors developed to date essentially measure photocurrents induced by the generation and separation of electron−hole pairs in semiconductors during irradiation. Although the above light detection method is well established, highly sensitive, and applicable to a broad range of semiconductor materials, it requires the presence of a stable and direct contact between the semiconductor and the electrode for accurate photocurrent measurements. In turn, this prerequisite necessitates the use of various costly processes for device fabrication (e.g., photolithography and vacuum deposition of semiconductors/metals) and complicates the development of flexible devices. Herein, inspired by the fact that the dielectric properties of certain materials can be changed by light irradiation, we dispersed ZnS/Cu semiconducting particles in poly(vinyl butyral) to prepare a free-standing composite film and formed two layers of Ag nanowire electrodes on both sides of the cured composite to fabricate a photodetector of a completely new type. The developed device exhibited a capacitance very sensitive to irradiation with light of a specific wavelength and additionally featured the advantages of simple structure/operation mechanism, mechanical flexibility, and transparency, not showing any signs of performance deterioration even after severe damage.
Recent studies are actively contributing to the implementation of the use of five human senses in electronic skins. In order to achieve this, it is critical to develop sensors with the ability to heal after being subjected to stretching or damage; this should be achieved without any significant deterioration in performance, as is possible for human skin. This study investigates the potential for producing stretchable, cuttable, and healable photodetectors. To this end, a reversibly cross‐linkable silicone polymer, polydimethylsiloxane (rcPDMS), is synthesized via a Diels–Alder reaction; subsequently, ZnS:Cu particles are dispersed therein to form a composite film. Ag nanowires (AgNWs) are formed on both the surfaces of the film to realize a three‐layer sandwich structured capacitor, namely: AgNWs/ZnS:Cu‐rcPDMS/AgNWs. Light irradiation of the film induces the photodielectric effect in ZnS:Cu particles and the dielectric response of photoinduced dipole moments composed of localized photoactive carriers results in a change in the capacitance of the film. Based on this, a photodetector is developed that is stretchable, healable, and demonstrates no reduction in the device performance even before and after cutting as well as healing.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.