RESUMEN
Molecular editing promises to facilitate the rapid diversification of complex molecular architectures by rapidly and conveniently altering core frameworks. This approach has the potential to accelerate both drug discovery and total synthesis. In this study, we present a novel protocol for the molecular editing of pyrroles. Initially, N-Boc pyrroles and alkynes are converted into N-bridged compounds through a Diels-Alder reaction. These compounds then undergo deprotection of the Boc group, nitrosylation, and cheletropic N2O extrusion to yield benzene or naphthalene products. By using benzyne as a substrate, this method can be conceptually viewed as a fusion of skeletal editing of the pyrrole ring and site-selective peripheral editing of the benzene ring. Furthermore, this proof-of-concept protocol has demonstrated its potential to transform the (hetero)arene motif from commercially available drugs, offering the possibility of generating new biologically active compounds.
RESUMEN
In this report, we present a photopromoted, metal-free transannulation of phenyl azides for the synthesis of DNA-encoded seven-membered rings. The transformation is efficiently achieved through a skeletal editing strategy targeting the benzene motif coupled with a Reversible Adsorption to Solid Support (RASS) strategy. A variety of valuable DNA-encoded seven-membered ring compounds, including DNA-encoded 3H-azepines, azepinones, and unnatural amino acids, are now accessible. Crucially, this DNA-compatible protocol can also be applied for the introduction of complex molecules, as exemplified by Lorcaserin and Betahistine. The selective conversion of readily available phenyl rings into high-value seven-membered rings offers a promising avenue for the construction of diversified and drug-like DNA-encoded library.
Asunto(s)
Azidas , Benceno , Ciclización , Aminas , ADNRESUMEN
The rational design and optimization of heterogeneous interface for low loading noble metal HER eletrocatalysts to facilitate the upscaling of alkaline water/seawater electrolysis is highly challenging. Herein, we present a facile deep corrosion strategy induced by NaBH4 to precisely construct an ultrasmall Ru nanoparticle-decorated Ni/NiO hybrid (r-Ru-Ni/NiO) with highly dispersed triple-phase heterostructures. Remarkably, it exhibits superior activity with only 53 mV and 70 mV at 100 mA cm-2 for hydrogen evolution reaction (HER) in alkaline water and seawater, respectively, surpassing the performance of Pt/C (109.7 mV, 100 mA cm-2, 1 M KOH). It is attributed to collaborative optimization of electroactive interfaces between well-distributed ultrasmall Ru nanoparticles and Ni/NiO hybrid. Moreover, the assembled r-Ru-Ni/NiO system just require 2.03 V at 1000 mA cm-2 in anion exchange membrane (AEM) electrolyzer, outperforming a RuO2/NF || Pt/C system, while exhibiting outstanding stability at high current densities. This study offers a logical design for accurate construction of interfacial engineering, showing promise for large-scale hydrogen production via electrochemical water splitting.
RESUMEN
The development of electrocatalysts that are not reliant on iridium for efficient acid-oxygen evolution is a critical step towards the proton exchange membrane water electrolysis (PEMWE) and green hydrogen industry. Ruthenium-based electrocatalysts have garnered widespread attention due to their remarkable catalytic activity and lower commercial price. However, the challenge lies in balancing the seesaw relationship between activity and stability of these electrocatalysts during the acid-oxygen evolution reaction (OER). This review delves into the progress made in Ru-based electrocatalysts with regards to acid OER and PEMWE applications. It highlights the significance of customizing the acidic OER mechanism of Ru-based electrocatalysts through the coordination of adsorption evolution mechanism (AEM) and lattice oxygen oxidation mechanism (LOM) to attain the ideal activity and stability relationship. The promising tradeoffs between the activity and stability of different Ru-based electrocatalysts, including Ru metals and alloys, Ru single-atomic materials, Ru oxides, and derived complexes, and Ru-based heterojunctions, as well as their applicability to PEMWE systems, are discussed in detail. Furthermore, this paper offers insights on in situ control of Ru active sites, dynamic catalytic mechanism, and commercial application of PEMWE. Based on three-way relationship between cost, activity, and stability, the perspectives and development are provided.