The direct difunctionalization of alkenes, a cheap and abundant feedstock, represents one of the most attractive strategies for increasing molecular complexity in synthetic organic chemistry. In ...contrast with the 1,2‐difunctionalization of alkenes, recent advances showcase alkene 1,n‐difunctionalizations (n≠2) involving metal migration is an emerging and rapidly growing area of research. This promising strategy not only opens a novel avenue for future development of alkene transformations, but also significantly expands upon the bond disconnections available in modern organic synthesis. This Minireview summarizes recent progress in the migratory difunctionalization of alkenes, with an emphasis on the driving force for metal migration.
Driving force: The difunctionalization of alkenes involving metal migration provides access to a new class of products that are not readily synthesized by other methods. This Minireview summarizes recent advances in the field, with an emphasis on the driving force for metal migration.
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The results of numerous studies have led to the development of supramolecular (assembled) organic substances for use in biomedical imaging as part of comprehensive approaches to the diagnosis of ...diseases. This review summarizes recent advances that have been made in the design and fabrication of assembled organic dyes for fluorescence and photoacoustic bioimaging.
The results of numerous studies have led to the development of assembled organic substances for fluorescence and photoacoustic bioimaging as part of comprehensive approaches to the diagnosis of diseases.
The Catellani reaction is known as a powerful strategy for the expeditious synthesis of highly substituted arenes and benzo‐fused rings, which are usually difficult to access through traditional ...cross‐coupling strategies. It utilizes the synergistic interplay of palladium and norbornene catalysis to facilitate sequential ortho C−H functionalization and ipso termination of aryl halides in a single operation. In classical Catellani‐type reactions, aryl halides are mainly used as the substrates, and a Pd0 catalyst is required to initiate the reaction. Nevertheless, recent advances showcase that Catellani‐type reactions can also be initiated by a PdII catalyst with different starting materials instead of aryl halides via different reaction mechanisms and under different conditions. This emerging concept of PdII/norbornene cooperative catalysis has significantly advanced Catellani‐type reactions, thus enabling future developments of this field. In this Minireview, PdII‐initiated Catellani‐type reactions and their application in the synthesis of bioactive molecules are summarized.
Cooperative solutions: Palladium(II)‐initiated norbornene (NBE)‐mediated cooperative catalysis has enabled significant developments of the Catellani reaction. These advances and their application in the synthesis of bioactive molecules are summarized in this Minireview.
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The use of boron dipyrromethene (BODIPY) in biomedicine is reviewed. To open, its synthesis and regulatory strategies are summarized, and inspiring cutting‐edge work in post‐functionalization ...strategies is highlighted. A brief overview of assembly model of BODIPY is then provided: BODIPY is introduced as a promising building block for the formation of single‐ and multicomponent self‐assembled systems, including nanostructures suitable for aqueous environments, thereby showing the great development potential of supramolecular assembly in biomedicine applications. The frontier progress of BODIPY in biomedical application is thereafter described, supported by examples of the frontiers of biomedical applications of BODIPY‐containing smart materials: it mainly involves the application of materials based on BODIPY building blocks and their assemblies in fluorescence bioimaging, photoacoustic imaging, disease treatment including photodynamic therapy, photothermal therapy, and immunotherapy. Lastly, not only the current status of the BODIPY family in the biomedical field but also the challenges worth considering are summarized. At the same time, insights into the future development prospects of biomedically applicable BODIPY are provided.
Boron dipyrromethene (BODIPY) is an outstanding fluorescent molecule, with high molar absorption coefficients and good chemical stability. Improvements in self‐assembly technology have fueled the applications of BODIPY in diagnosis and treatment. This review summarizes the molecular structure design and self‐assembly strategy of BODIPY, and its applications as a multifunctional theranostic agent in biomedical fields.
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Azobenzene is a well‐known derivative of stimulus‐responsive molecular switches and has shown superior performance as a functional material in biomedical applications. The results of multiple studies ...have led to the development of light/hypoxia‐responsive azobenzene for biomedical use. In recent years, long‐wavelength‐responsive azobenzene has been developed. Matching the longer wavelength absorption and hypoxia‐response characteristics of the azobenzene switch unit to the bio‐optical window results in a large and effective stimulus response. In addition, azobenzene has been used as a hypoxia‐sensitive connector via biological cleavage under appropriate stimulus conditions. This has resulted in on/off state switching of properties such as pharmacology and fluorescence activity. Herein, recent advances in the design and fabrication of azobenzene as a trigger in biomedicine are summarized.
Azobenzene is a well‐known derivative of stimulus‐responsive molecular switches and has shown superior performance as a functional material in biomedical applications. The results of numerous studies have led to the development of light/hypoxia‐responsive azobenzene for biomedical use. Recent advances in the design and fabrication of azobenzene as a trigger in biomedicine are summarized.
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Diarylethene (DAE) photoswitch is a new and promising family of photochromic molecules and has shown superior performance as a smart trigger in stimulus‐responsive materials. During the past few ...decades, the DAE family has achieved a leap from simple molecules to functional molecules and developed toward validity as a universal switching building block. In recent years, the introduction of DAE into an assembly system has been an attractive strategy that enables the photochromic behavior of the building blocks to be manifested at the level of the entire system, beyond the DAE unit itself. This assembly‐based strategy will bring many unexpected results that promote the design and manufacture of a new generation of advanced materials. Here, recent advances in the design and fabrication of diarylethene as a trigger in materials science, chemistry, and biomedicine are reviewed.
Diarylethenes are a new type of photochromic molecules with attractive photofatigue resistance and reversibility. The result of a lot of effort has led to the rapid development of photoresponsive diarylethylenes for smart material applications. The recent advances in the design and assembly of diarylethylene as a multifunctional photoresponsive trigger unit are reviewed.
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Catalytic C−H functionalization has emerged as an efficient alternative to traditional coupling reactions. However, some of these reactions depend on environmentally harmful solvents, weakening the ...overall green nature of these methods. As organic processes consume large amount of solvents, the use of less harmful solvents enhance the sustainability of these reactions. Herein, we present an overview of transition metal‐catalyzed C−H functionalization reactions for the synthesis of heterocycles in sustainable solvents based on CHEM21 solvent selection guide.
Towards green: This Minireview highlights the improved greenness of the transition metal‐catalyzed C−H functionalization using sustainable solvent for the synthesis of heterocycles in a high atom‐ and step‐economical manner.
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A highly diastereoselective method for the synthesis of dihydroepoxybenzofluorenone derivatives from aromatic/vinylic amides and bicyclic alkenes is described. This new transformation proceeds ...through cobalt‐catalyzed C−H activation and intramolecular nucleophilic addition to the amide functional group. Transition‐metal‐catalyzed C−H activation reactions of secondary amides with alkenes usually lead to 4+2 or 4+1 annulation; to the best of our knowledge, this is the first time that a 3+2 cycloaddition is described in this context. The reaction proceeds under mild conditions and tolerates a wide range of functional groups. Mechanistic studies imply that the C−H bond cleavage may be the rate‐limiting step.
3+2 instead of 4+2 or 4+1: The diastereoselective 3+2 annulation of secondary amides with alkenes proceeds by cobalt‐catalyzed C−H activation and intramolecular nucleophilic addition to the amide functional group under mild conditions. Mechanistic studies suggest that the C−H bond cleavage is the rate‐limiting step.
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Chiral tetrahydrocarbazoles (THCs) are prevalent in numerous natural indole alkaloids as well as synthetic pharmaceuticals, and exhibit a broad spectrum of bioactivities. As such, the development of ...efficient synthetic methodologies for the synthesis of chiral THCs is of substantial interest. The advent of asymmetric catalysis provides a powerful platform to assemble chiral THC motifs and great efforts have been devoted to this field over the past decades. In this feature article, we summarise recent advances in catalytic asymmetric synthesis of THCs, with particular emphases on reaction types and reaction mechanism.
This feature article summarises recent advances in catalytic asymmetric synthesis of THCs, with emphases on reaction type and reaction mechanism.
The 2019 novel coronavirus (2019-nCoV) causing an outbreak of pneumonia in Wuhan, Hubei province of China was isolated in January 2020. This study aims to investigate its epidemiologic history, and ...analyze the clinical characteristics, treatment regimens, and prognosis of patients infected with 2019-nCoV during this outbreak.
Clinical data from 137 2019-nCoV-infected patients admitted to the respiratory departments of nine tertiary hospitals in Hubei province from December 30, 2019 to January 24, 2020 were retrospectively collected, including general status, clinical manifestations, laboratory test results, imaging characteristics, and treatment regimens.
None of the 137 patients (61 males, 76 females, aged 20-83 years, median age 57 years) had a definite history of exposure to Huanan Seafood Wholesale Market. Major initial symptoms included fever (112/137, 81.8%), coughing (66/137, 48.2%), and muscle pain or fatigue (44/137, 32.1%), with other, less typical initial symptoms observed at low frequency, including heart palpitations, diarrhea, and headache. Nearly 80% of the patients had normal or decreased white blood cell counts, and 72.3% (99/137) had lymphocytopenia. Lung involvement was present in all cases, with most chest computed tomography scans showing lesions in multiple lung lobes, some of which were dense; ground-glass opacity co-existed with consolidation shadows or cord-like shadows. Given the lack of effective drugs, treatment focused on symptomatic and respiratory support. Immunoglobulin G was delivered to some critically ill patients according to their conditions. Systemic corticosteroid treatment did not show significant benefits. Notably, early respiratory support facilitated disease recovery and improved prognosis. The risk of death was primarily associated with age, underlying chronic diseases, and median interval from the appearance of initial symptoms to dyspnea.
The majority of patients with 2019-nCoV pneumonia present with fever as the first symptom, and most of them still showed typical manifestations of viral pneumonia on chest imaging. Middle-aged and elderly patients with underlying comorbidities are susceptible to respiratory failure and may have a poorer prognosis.
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