Recent Advances in the Electrochemical Defluorinative Transformations of C-F Bonds

Organic fluorine compounds are ubiquitous and pivotally important organic molecules,yet their activation and transformation have long been a formidable challenge due to the high energy and low reactivity of C-F bonds.Organic electrosynthesis,an environmentally benign synthetic method in organic chemistry,enables a myriad of chemical transformations without the need for external redox reagents.In recent years,organic electrochemistry has emerged as a powerful tool for achieving the activation and transformation of C-F bonds in fluorine-containing compounds.This review aims to succinctly recapitulate the latest advancements in the electrochemical defluorinative transformations of C-F bonds and to delve into the reaction design,mechanistic insights,and developmental prospects ofthese methods.

Rhodium-Catalyzed Transannulation of 1,2,3-Thiazoles with Alkynes for the Direct Synthesis of Thiochromenones

A rhodium-catalyzed denitrogenative carbonylation of 1,2,3-thiadiazole with alkynes to construct(benzo)thiochromenones is developed.Both terminal and internal alkynes were compatible in this[3+2+1]cycloaddition,affording a broad range of poly-substituted thiochromenones.Unsymmetrical alkyne substrates exhibited good regioselectivity.

Tracking the Process of Domino Ring-Opening and Coupling of Fused Imidazole and Direct Observation of Peroxide Intermediates

Comprehensive Summary,A domino ring-opening and coupling of imidazolyl annulated heterocycles 1(1a:4-methyl-1-(1-methyl-1H-benzo[d]imidazol-2-yl)-4H-benzo[d]imidazo[1,5-a]imidazole,1b:1-(1,5-dimethyl-1H-benzo[d]imidazol-2-yl)-4,7-dimethyl-4H-benzo[d]imidazo[1,5-a]imidazole)with dioxygen was developed at solvothermal condition,leading to conjugated 1,2-diamidoalkenes derivatives 2((E)-ArCONHArC=CArNHCOAr(Ar:1-methyl-1H-benzo[d]imidazolyl(2a),1,5-dimethyl-1H-benzo[d]imidazolyl(2b)))as single crystals directly.The reaction process was tracked by electrospray ionization mass spectrometry(ESI-HRMS)and a series of reaction intermediates are detected.^(18)O_(2) labeling experiment verified the source of oxygen in 2.Combining evidence from control experiments,nuclear magnetic resonance(NMR)tracking,and crystallography,a seven-step reaction pathway involving oxygen addition,ring opening,Friedel-Crafts alkylation,oxidation,and dehydration was proposed and further supported by DFT calculation.

Recent progress in the structural study of ion channels as insecticide targets

Ion channels,many expressed in insect neural and muscular systems,have drawn huge attention as primary targets of insecticides.With the recent technical breakthroughs in structural biology,especially in cryo-electron microscopy(cryo-EM),many new high-resolution structures of ion channel targets,apo or in complex with insecticides,have been solved,shedding light on the molecular mechanism of action of the insecticides and resistance mutations.These structures also provide accurate templates for structure-based insecticide screening and rational design.This review summarizes the recent progress in the structural studies of 5 ion channel families:the ryanodine receptor(RyR),the nicotinic acetylcholine receptor(nAChR),the voltage-gated sodium channel(VGSC),the transient receptor potential(TRP)channel,and the ligand-gated chloride channel(LGCC).We address the selectivity of the channel-targeting insecticides by examining the conservation of key coordinating residues revealed by the structures.The possible resistance mechanisms are proposed based on the locations of the identified resistance mutations on the 3D structures of the target channels and their impacts on the binding of insecticides.Finally,we discuss how to develop“green”insecticides with a novel mode of action based on these high-resolution structures to overcome the resistance.

Laccase-functionalized magnetic framework composite enabled chlorophenols degradation,a potential remediation for fungicides residues in leather

Chlorophenols,used as the fungicides in leather,are strictly limited in leather products.In this work,a metal-organic framework material,zeolitic metal azolate framework-7(MAF-7),was first used to encapsulate laccase(Lac)to prepare MAF-7/Lac bio-composites with 98.5%immobilization yield.Afterward,Lac/MNP@MOM was formed by introducing the magnetic nanoparticles(MNPs)into the Lac@MOM.MAF-7 with better hydrophilicity and stronger pH buffering ability,exhibits good compatibility with laccase,which can reserve the activity of laccase after immobilization.Moreover,the porous structure of MAF-7 is favorable for the sufficient contact between laccase and substrates.Lac/MNP@MOM exhibited excellent activity when exposed to high temperature,extreme pH,and organic solvents,which also simplified complex recovery steps.Furthermore,the degradation rate of 2,4-dichlorophenol(2,4-DCP)could reach as high as 97%within 24 h by immobilized laccase,and after nine consecutive cycles of operation,enzyme activity could remain over 80%,which gives it the potential for practical applications.