bluuebunny/crossref_metadata_2025_split huggingface dataset:
CH Functionalization Using Carboxylic Acids and Carboxylic Acid Derivatives as Electrophiles under Redox‐Neutral Conditions
Authors: Gao Pengcheng , Meng Guangrong , Hammadi Batoul , Szostak Michal 
Published: October 2022

Abstract
The article provides a summary of the recent developments in using carboxylic acids and derivatives as aryl, alkenyl, and alkyl electrophiles for CH functionalization. This manifold exploits ubiquitous carboxylic acids as electrophiles after oxidative addition and decarbonylation in the absence of external oxidants under Rh, Pd, Ni, and Ir catalysis. Mechanistically, acyl RC(O)X bond oxidative addition to low valent metals is followed by decarbonylation, resulting in a net generation of R[M] electrophiles for a broad range of CH functionalization processes. The article covers aroyl chlorides, aroyl fluorides, anhydrides, carboxylic acids, esters and amides, and other related acyl derivatives.
Iron‐Catalyzed Nitrene Insertion of CH Bonds
Authors: Zhong Dayou , Zheng Yu‐Qing , Liu Wen‐Bo 
Published: October 2022

Abstract
Nitrene insertion of CH bonds represents a powerful synthetic method to form nitrogen‐containing organic compounds. This article summarized recent development of iron‐catalyzed nitrene insertion of CH bonds for the construction of CN bonds and organized by the types of nitrene precursors, including iminoiodanes, organic azides, hydroxylamine derivatives, sulfonamides, etc. Important examples and breakthroughs in this field are highlighted, and the current mechanistic understandings of the formation of iron‐nitrenoid species and the catalytic cycles are discussed. Additionally, the synthetic application of this chemistry is also included.
CH Functionalization Reactions Promoted by First‐Row Transition Metals with Redox‐Active Ligands. Nature Did it First
Authors: Wu Tong , Hebert David D. , Puri Ankita , Garcia‐Bosch Isaac 
Published: October 2022

Abstract
Some natural metalloenzymes carry out challenging organic transformations utilizing 3d metals (e.g. Fe and Cu) in combination with redox‐active moieties. Based on the exquisite reactivity of these natural catalysts, we compiled the most relevant examples of CH functionalization reactions promoted by 3d metals that cooperate with redox‐active supporting ligands, oxidants, and substrates.
Inner‐Sphere CH Bond Activation
Authors: Mahato Rina , Sharma Pragya , Hazra Chinmoy K. 
Published: October 2022

AbstractTransition metal‐catalyzed inert C(sp2)H and C(sp3)H bond activation is an emerging approach for introducing desired functionality to a specific location. This article describes the regioselective functionalization of aryl/alkyl moieties for the synthesis of useful compounds and molecular materials. A wide range of directing‐group assisted CH activation reactions, and some of the most well‐known regio‐controlled reactions via noncovalent interactions have been addressed. This distance‐ and geometry‐based differentiation technique for regioselective distant CH activation not only led to the desired site but also reduces the reaction time and waste. Additionally, more challenging distal gamma and delta C(sp3)H bond functionalization is another striking feature appearing in this enclosed article.
CH Functionalization via Chalcogen and Pnictogen Salts
Authors: Kelly Christopher B. , Padilla‐Salinas Rosaura 
Published: October 2022

Abstract
CH functionalization is an enabling technology for medicinal chemistry efforts, allowing a greater chemical landscape to be assayed in a shorter time frame from non‐pre‐functionalized materials. Part of an elite class of the so‐called late‐stage functionalization (LSF) reactions, CH functionalization can take many forms, with one emerging form involving the intermediacy of chalcogen and pnictogen salts. Although canonical boronate esters or halides are the “go‐to” species for CH functionalization, three unrelated cationic groups (phosphonium, pyridinium, and thianthrenium) have emerged as viable alternatives with rich avenues for diversification. Despite being a two‐step process to achieve the net desired CH transformation, the ease of entry and the unusual regiochemical selectivity of salt formation make these chalcogen and pnictogen indispensable assets to LSF efforts. This article details the fundamentals of using these salts for CH functionalization, with an emphasis on how they can be enabling technologies for medicinal chemistry.
HFIP‐Mediated CH Functionalization
Authors: Solyev Pavel N. 
Published: October 2022

Abstract
1,1,1,3,3,3‐Hexafluoroisopropanol (HFIP) is a solvent with properties in the extreme. Being used in specific scopes for more than half a century, nowadays, it has become a hot topic in complex organic transformations. The application of HFIP is gaining wide perspectives not only in synthetic chemistry but in biology and chemical physics. This article discloses the unusual nature of HFIP and its extraordinary solvation effects upon different classes of molecules and on CH functionalization reactions in general. The structure and coordinating modes of the solvent make it possible to infer the impact of HFIP on the reagents activation, intermediates stabilization, and products outcome in CH functionalization reactions.
CH Functionalization Reactions Following a Single‐Electron Transfer and Radical Pathway
Authors: Bains Amreen K. , Adhikari Debashis 
Published: October 2022

Abstract
The CH functionalization reactions are of utmost importance in synthetic chemistry and multiple approaches have been adopted to discover easy and mild processes. This article focuses on CH functionalization reactions that are predominantly promoted by radical species. Many prior processes often rely on prefunctionalization of a particular CH bond, hence a direct method without such prior activation would be very much appreciable. In a radical‐driven CH functionalization process, an alkyl or aryl radical can be generated from an appropriate precursor by single electron transfer event. Beyond that, a significant effort is devoted to discover new precursor molecules from which a variety of alkyl and aryl radicals will be efficiently generated. The mildness of the process is often demonstrated by the chemoselectivity, and a wide functional group tolerance. The applicability of the radical‐mediated CH functionalization processes stretches further to the realm of medicinally and pharmaceutically important molecules. Additionally, many photochemical processes are recent addition to the repertoire of radical generation that facilitate the methods without any heating. Intriguing mechanistic scenarios for radical generation and further reactions toward CH functionalization is described and discussed.
Direct CH (Het)arylation of 1,2‐Heteroazoles, Heterodiazoles, and Triazoles
Authors: Koyioni Maria , Koutentis Panayiotis A. 
Published: October 2022

Abstract
Recent developments in the direct CH (het)arylation of 1,2‐heteroazoles, heterodiazoles, and triazoles are reviewed, i.e. pyrazoles, isoxazoles, isothiadiazoles, triazoles oxadiazoles, thiadiazoles, and their arene‐fused analogs. Reaction scope and mechanistic considerations are reported. The direct arylation of “unactivated” CH bonds avoids procedures that require prefunctionalization of the substrate, making such synthesis more cost‐effective and atom economic as well as avoiding the generation of stoichiometric amounts of toxic waste. As such, this synthetically valuable strategy has been applied to a broad array of (het)arenes. This article covers the direct CH (het)arylation of less common, heteroatom‐rich azoles from 1982, the first reported reaction, to the present day.
Copper in CH Functionalization: Mechanistic Insights into CH to CC/N/O Transformations
Authors: Gayathri K. , Kundu Subrata 
Published: October 2022

Abstract
This article illustrates a diverse array of copper‐mediated CH to CX (X = C/N/O) transformations. Moreover, the examples are discussed to underscore the possible copper‐containing intermediates by emphasizing the routes for the generation of the catalytically viable intermediates and their reactivity trends relevant to CH to CX transformations. In contrast to the organometallic pathways commonly preferred by the 2nd and 3rd row transition metal‐catalyzed CH to CX (X = C/N/O) transforming routes, the routes involving copper sites have been illustrated to involve both organometallic as well as outer sphere mechanisms. Consequently, the copper‐mediated CH functionalization routes utilize a combination of both 1e‐ and 2e‐ steps. Thus, a detailed understanding of the mechanism is critical for the rational design of the catalyst as well as the methods.
Electrochemical Oxidative CH Functionalization: A Metal‐Free Approach
Authors: Ghosh Adrija , Bera Atanu , Bera Sourajit , Banerjee Debasis 
Published: October 2022

Abstract
Electrochemical CH bond functionalization of organic molecules has emerged as one of the most powerful tools for the synthesis of carbon–carbon and carbon–heteroatom bonds. In past decades, metal‐catalyzed CH activation has attracted significant attention owing to the drawbacks of the conventional methods. At the same time, classical approaches suffer from serious limitations such as the use of expensive catalytic systems, toxic reagents, harsh reaction conditions, and additional waste generation. This has highlighted the need for a sustainable and atom‐efficient solution in the form of various modern‐day techniques. Metal‐ and oxidant‐free electrochemical CH functionalization has proved to be an efficient alternative in terms of efficacy as well as atom economy. Herein, we have discussed about the contribution of metal‐free oxidative electrochemical CH activation in the construction of challenging CC and C–heteroatom (CN, CO, CS, C–halogen) bonds. Detailed mechanistic descriptions and applications toward synthesis of bio‐active drug molecules are also considered till April 2021.
Structurally Defined Molecular Bismuth Compounds in CH Activation
Authors: Oberdorf Kai , Lichtenberg Crispin 
Published: October 2022

Abstract
With their low costs, ready availability, and relatively low toxicity, bismuth and its compounds offer interesting properties for the use as reagents in synthetic chemistry. Furthermore, bismuth is a heavy metal with a large covalent and ionic radius and a range of accessible coordination geometries and oxidation states, which allows for careful complex design in order to address desired reactivity patterns. The scientific efforts toward the exploitation of bismuth compounds for unusual CH activation reactions are summarized in this contribution with a focus on the different types of synthetic strategies that have been elaborated.
Directing Group‐Assisted CH Bond Functionalization on the Naphthalene
Authors: Ghosh Subhash Chandra 
Published: October 2022

Abstract
The direct functionalization of CH bonds is now considered an attractive, powerful, and step‐economical tool in organic synthesis. Regioselective CH functionalization of arenes implies the installation of a functional group on the desired position of the ring of mono‐substituted arenes. Naphthalene is a privileged aromatic compound that is widely presented in numerous pharmaceuticals, agrochemicals, dyes, and functional materials. Consequently, a lot of research has been carried out in the past decade to develop new methodologies to install a functional group on every possible position of the naphthalene nucleus. In this article, we have summarized the regioselective functionalization of mono‐substituted naphthalene via directing group assistance strategy.
Late‐Stage CH Functionalizations Directed by Nickel Catalysis and Its Implications on Total Synthesis of Natural Products
Authors: Kokkonda Praveen , Deb Arghya 
Published: October 2022

Abstract
The predominant existence of CH bonds in plethora of natural products influence the synthetic chemist to develop reactions by utilizing CH functionalization for directly generating valuable products from simple feedstock. Due to low cost, easy availability and unique reactivity profiles, tremendous advancement in the field of CH functionalization has been achieved by first‐row transition metals and been recognized as the potential alternative to noble transition metals. Among these, nickel has drawn considerable attentions as due to it's potential in diverse mechanistically different reactions, entrapping both the classical organometallic and radical‐based intermediates. This book chapter focuses on Ni‐catalyzed CH functionalization reactions by which challenging late stage functionalization and a number of total synthesis of natural products were achieved.
Electrophotocatalytic CH Bonds Functionalization
Authors: Wang Kui , Wang Hong , Wang Aihua , Liu Siyuan , Ma Li , Gao Wei , Chen Jianbin 
Published: October 2022

Abstract

Synthetic photoelectrochemistry (PEC), the fusion of photoredox catalysis (PRC), and synthetic organic electrochemistry (SOE) provide a powerful way for the selective C(sp
2
)/C(sp
3
)H functionalization via single‐electron transfer (SET). Compared with PRC and SOE, PEC shows stronger redox ability under mild conditions and significant atomic and energy economy. The combination of PEC with hydrogen atom transfer (HAT) makes the inert CH activation possible. Herein, the corresponding work is reviewed by the classification of the formation of CO, CC, CN, and CP bonds.
Ru‐Catalyzed C(sp
3
)H Functionalization
Authors: Murugesh V. , Sahoo Apurba Ranjan , Achard Mathieu , Suresh Surisetti 
Published: October 2022

Abstract

Selective C(sp
3
)H activation/functionalization is one of the most challenging transformations in the modern synthetic organic chemistry. A number of ruthenium(0) and ruthenium(II) complexes have shown remarkable efficiency in this regard. This article aims to concentrate on the notable advancements in this field of ruthenium‐induced C(sp
3
)H activation of amines, alcohols, ketones, and alkanes.
Ru‐Catalyzed CH Functionalization of Heterocycles
Authors: Bai Ruopeng , Shan Chunhui , Lan Yu 
Published: October 2022

Abstract
Heterocycles are key structural motifs in a variety of organic functional compounds, which are widely used in organic chemistry, pharmaceutical sciences, optoelectronics, and material science. In recent years, direct CH bond activation/functionalization has become a promising and attractive synthetic strategy and has been widely applied to construct new CC and Cheteroatom bonds. This article focuses on recent progress in ruthenium‐catalyzed‐directed CH functionalization of heterocycles, including CH alkylation, alkenylation, and alkynylation. In addition, due to the importance and rapid progress in photocatalysis, pioneering work was also summarized in the field of photoredox CH heterocycles functionalization employing ruthenium as photocatalyst.
Comparison of plasma and CSF biomarkers in predicting cognitive decline
Authors: Aschenbrenner Andrew J. , Li Yan , Henson Rachel L. , Volluz Katherine , Hassenstab Jason , Verghese Philip , West Tim , Meyer Matthew R. , Kirmess Kristopher M. , Fagan Anne M. , Xiong Chengjie , Holtzman David , Morris John C. , Bateman Randall J. , Schindler Suzanne E. 
Published: October 2022

AbstractObjectivesConcentrations of amyloid‐β peptides (Aβ42/Aβ40) and neurofilament light (NfL) can be measured in plasma or cerebrospinal fluid (CSF) and are associated with Alzheimer’s disease brain pathology and cognitive impairment. This study directly compared plasma and CSF measures of Aβ42/Aβ40 and NfL as predictors of cognitive decline.MethodsParticipants were 65 years or older and cognitively normal at baseline with at least one follow‐up cognitive assessment. Analytes were measured with the following types of assays: plasma Aβ42/Aβ40, immunoprecipitation‐mass spectrometry; plasma NfL, Simoa; CSF Aβ42/Aβ40, automated immunoassay; CSF NfL plate‐based immunoassay. Mixed effects models evaluated the global cognitive composite score over a maximum of 6 years as predicted by the fluid biomarkers.ResultsAnalyses included 371 cognitively normal participants, aged 72.7 ± 5.2 years (mean ± standard deviation) with an average length of follow‐up of 3.9 ± 1.6 years. Standardized concentrations of biomarkers were associated with annualized cognitive change: plasma Aβ42/Aβ40, 0.014 standard deviations (95% confidence intervals 0.002 to 0.026); CSF Aβ42/Aβ40, 0.020 (0.008 to 0.032); plasma Nfl, −0.018 (−0.030 to −0.005); and CSF NfL, −0.024 (−0.036 to −0.012). Power analyses estimated that 266 individuals in each treatment arm would be needed to detect a 50% slowing of decline if identified by abnormal plasma measures versus 229 for CSF measures.InterpretationBoth plasma and CSF measures of Aβ42/Aβ40 and NfL predicted cognitive decline. A clinical trial that enrolled individuals based on abnormal plasma Aβ42/Aβ40 and NfL levels would require only a marginally larger cohort than if CSF measures were used.
Bioinspired and Inflammation‐Modulatory Glycopeptide Hydrogels for Radiation‐Induced Chronic Skin Injury Repair
Authors: Feng Zujian , Zhang Yumin , Yang Chunfang , Liu Xiang , Huangfu Yini , Zhang Chuangnian , Huang Pingsheng , Dong Anjie , Liu Jinjian , Liu Jianfeng , Kong Deling , Wang Weiwei 
Published: October 2022

AbstractClinical wound management of radiation‐induced skin injury (RSI) remains a great challenge due to acute injuries induced by excessive reactive oxygen species (ROS), and the concomitant repetitive inflammatory microenvironment caused by an imbalance in macrophage homeostasis. Herein, a cutaneous extracellular matrix (ECM)‐inspired glycopeptide hydrogel (GK@TAgel) is rationally designed for accelerating wound healing through modulating the chronic inflammation in RSI. The glycopeptide hydrogel not only replicates ECM‐like glycoprotein components and nanofibrous architecture, but also displays effective ROS scavenging and radioprotective capability that can reduce the acute injuries after exposure to irradiation. Importantly, the mannose receptor (MR) in GK@TAgel exhibits high affinity and bioactivity to drive the M2 macrophage polarization, thereby overcoming the persistent inflammatory microenvironment in chronic RSI. The repair of RSI in mice demonstrates that GK@TAgel significantly reduces the hyperplasia of epithelial, promotes appendage regeneration and angiogenesis, and decreased the proinflammatory cytokine expression, which is superior to the treatment of commercial radioprotective drug amifostine. Collectively, the ECM‐mimetic hydrogel dressing can protect the tissue from irradiation and heal the chronic wound in RSI, holding great potential in clinical wound management and tissue regeneration.
A Conductive Hydrogel Microneedle‐Based Assay Integrating PEDOT:PSS and Ag‐Pt Nanoparticles for Real‐Time, Enzyme‐Less, and Electrochemical Sensing of Glucose
Authors: GhavamiNejad Peyman , GhavamiNejad Amin , Zheng Hanjia , Dhingra Karan , Samarikhalaj Melisa , Poudineh Mahla 
Published: October 2022

AbstractContinuous glucose meters (CGMs) have tremendously boosted diabetes care by emancipating millions of diabetic patients’ need for repeated self‐testing by pricking their fingers every few hours. However, CGMs still suffer from major deficiencies regarding accuracy, precision, and stability. This is mainly due to their dependency on an enzymatic detection mechanism. Here a low‐cost hydrogel microneedle (HMN)‐CGM assay fabricated using swellable dopamine (DA)‐hyaluronic acid (HA) hydrogel for glucose interrogation in dermal interstitial fluid (ISF) is introduced. Platinum and silver nanoparticles are synthesized within the 3D porous hydrogel scaffolds for nonenzymatic electrochemical sensing of the glucose. Incorporation of a highly water dispersible conductive polymer, poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) enhances the electrical properties of HMN array, making the patch suitable as the working electrode of the sensor. The in vitro and ex vivo characterization of this newly developed HMN patch is fully studied. The performance of the HMN‐CGM for real‐time measurement of glucose is also shown using a rat model of type 1 diabetes. The device introduces the first HMN‐based assay for tracking important disease biomarkers and expect to pave the way for next generation of polymeric‐based sensors.
Multi‐walled carbon nanotubes/carbon fiber fabric multiscale hybrid materials for improving the mechanical and tribological properties of phenolic resin composites
Authors: Wang Beibei , Fu Qiangang , Liu Yue , Lu Zhenyuan , Lu Yaru , Cao Sheng 
Published: October 2022

AbstractMulti‐walled carbon nanotubes (MWCNT)/carbon fiber fabric multiscale hybrid materials were prepared by grafting MWCNT on carbon fabric surface via heating grafted method to improve the mechanical and tribological properties of phenolic resin composites. Field emission scanning electron microscopy, Raman spectrometer, and X‐ray photoelectron spectroscopy were used to analyze the surface properties of carbon fiber. The results shown that the tensile strength of composites modified by 0.15 wt% MWCNT was 38% higher than that of unmodified composites. The wear rates decreased from 3.31 × 10−14 m3 (N·m)−1 for unmodified composites to 0.68 × 10−14 m3 (N·m)−1 for 0.15 wt% MWCNT reinforced composites. The reason was that the uniformly distributed MWCNT could increase interface interaction and mechanical interlocking between carbon fiber fabric and resin matrix.
Examining the relationship between cognitive inflexibility and internalizing and externalizing symptoms in autistic children and adolescents: A systematic review and meta‐analysis
Authors: Lei Jiedi , Charman Tony , Leigh Eleanor , Russell Ailsa , Mohamed Zameer , Hollocks Matthew J. 
Published: October 2022

AbstractCompared to neurotypical peers, autistic adolescents show greater cognitive inflexibility (CI) which manifests at the behavioral and cognitive level and potentially increases vulnerability for the development of internalizing (INT) and externalizing (EXT) symptoms. This systematic review and meta‐analysis explored the association between CI and INT/EXT in autistic adolescents. PubMed, EMBASE, MEDLINE, PsycINFO and Web of Science databases were searched to identify relevant studies until April 2022 (PROSPERO protocol: CRD42021277294). Systematic review included 21 studies (n = 1608) of CI and INT, and 15 studies (n = 1115) of CI and EXT. A pooled effect size using Pearson's correlation between CI and INT/EXT was calculated and the moderating effects of age, sex, IQ and study quality were investigated using meta‐regressions. Sensitivity analyses were completed to investigate the impact of measure variance for CI and co‐occurring ADHD on the overall effects. Greater CI is associated with increased INT (nine studies; n = 833; r = 0.39 (moderate effect), 95% confidence interval [0.32, 0.46]) and EXT (six studies; n = 295; r = 0.48 (large effect), 95% confidence interval [0.38, 0.58]). Results withheld when only using parental reports of CI and excluding autistic adolescents with co‐occurring ADHD. Increased CI may be a transdiagnostic vulnerability factor that can increase autistic adolescents' rigid or perseverative patterns of unhelpful cognition and behaviors and reduce their ability to access psychological interventions. Addressing CI may improve autistic children and adolescents' engagement with psychological therapy for co‐occurring mental health difficulties.