Visible-Light Photoredox Catalysis Xuan, Jun; Xiao, Wen-Jing
Angewandte Chemie (International ed.),
July 9, 2012, Letnik:
51, Številka:
28
Journal Article
Recenzirano
In the last few years, visible‐light initiated organic transformations have attracted increasing attention. The development of visible‐light‐promoted photocatalytic reactions, which enable rapid and ...efficient synthesis of fine chemicals, is highly desirable from the viewpoint of cost, safety, availability, and environmental friendliness. In this Minireview, recent advances made in this fast developing area of research are discussed.
In the spotlight: The title catalysis is an area of research that is developing quickly and has become a powerful and efficient tool in synthetic organic chemistry (see picture, S=Substrates, P=Products). There is little doubt that continued exploration of visible light photoredox catalysis will uncover a wide range of fascinating and useful chemical reactions.
Gladiolus hybridus is one of the most popular flowers worldwide. However, its corm dormancy characteristic largely limits its off‐season production. Long‐term cold treatment (LT), which increases ...sugar content and reduces abscisic acid (ABA), is an efficient approach to accelerate corm dormancy release (CDR). Here, we identified a GhbZIP30‐GhCCCH17 module that mediates the antagonism between sugars and ABA during CDR. We showed that sugars promoted CDR by reducing ABA levels in Gladiolus. Our data demonstrated that GhbZIP30 transcription factor directly binds the GhCCCH17 zinc finger promoter and activates its transcription, confirmed by yeast one‐hybrid, dual‐luciferase (Dual‐LUC), chromatin immunoprecipitation‐quantitative PCR (ChIP‐qPCR) and electrophoretic mobility shift assay (EMSA). GhCCCH17 is a transcriptional activator, and its nuclear localisation is altered by surcose and cytokinin treatments. Both GhbZIP30 and GhCCCH17 positively respond to LT, sugars, and cytokinin treatments. Silencing GhbZIP30 or GhCCCH17 resulted in delayed CDR by regulating ABA metabolic genes, while their overexpression promoted CDR. Taken together, we propose that the GhbZIP30‐GhCCCH17 module is involved in cold‐ and glucose‐induced CDR by regulating ABA metabolic genes.
Brief Summary
Sugars are regarded as integrators of environmental and endogenous signals. However, the relationship between abscisic acid (ABA) and sugars in the process of geophyte dormancy release is still unclear. In this study, we demonstrated that glucose plays a positive role in CDR in Gladiolus by decreasing endogenous ABA. We propose a GhbZIP30‐GhCCCH17 module that mediates the antagonism between sugars and ABA during CDR by regulating ABA metabolic genes.
Significance Statement
During cold storage of Gladiolus cormels, endogenous glucose and sucrose levels increase, which repress endogenous abscisic acid (ABA) and contribute to corm dormancy release (CDR). During this process, GhbZIP30 directly binds the GhCCCH17 promoter and activates its transcription. The GhbZIP30‐GhCCCH17 module is involved in cold‐ and glucose‐induced CDR by regulating ABA metabolic genes.
Visible‐light‐induced radical decarboxylative functionalization of carboxylic acids and their derivatives has recently received considerable attention as a novel and efficient method to create CC ...and CX bonds. Generally, this visible‐light‐promoted decarboxylation process can smoothly occur under mild reaction conditions with a broad range of substrates and an excellent functional‐group tolerance. The radical species formed from the decarboxylation step can participate in not only single photocatalytic transformations, but also dual‐catalytic cross‐coupling reactions by combining photoredox catalysis with other catalytic processes. Recent advances in this research area are discussed herein.
Photo op: A novel functionalization reaction using visible‐light‐induced photoredox catalysis has recently been developed (see title). The formed radical species can participate in not only single photocatalytic transformations, but also dual‐catalytic reactions by combining photoredox catalysis with other catalytic methods. Recent advances in this research area are discussed herein.
Thermal C-C bond cleavage reactions allow the construction of structurally diverse molecular skeletons via predictable and efficient bond reorganizations. Visible light photoredox-catalyzed ...radical-mediated C-C bond cleavage reactions have recently emerged as a powerful alternative method for overcoming the thermodynamic and kinetic barrier of C-C bond cleavage in diverse molecular scaffolds. In recent years, a plethora of elegant and useful reactions have been invented, and the products are sometimes otherwise inaccessible by classic thermal reactions. Considering the great influence and synthetic potential of these reactions, we provide a summary of the state of art visible light-driven radical-mediated C-C bond cleavage/functionalization strategies with a specific emphasis on the working models. We hoped that this review will be useful for medicinal and synthetic organic chemists and will inspire further reaction development in this interesting area.
Visible‐light photocatalysis is a rapidly developing and powerful strategy to initiate organic transformations, as it closely adheres to the tenants of green and sustainable chemistry. Generally, ...most visible‐light‐induced photochemical reactions occur through single‐electron transfer (SET) pathways. Recently, visible‐light‐induced energy‐transfer (EnT) reactions have received considerable attentions from the synthetic community as this strategy provides a distinct reaction pathway, and remarkable achievements have been made in this field. In this Review, we highlight the most recent advances in visible‐light‐induced EnT reactions.
Making light of synthesis: The distinctive reaction pathways provided by visible‐light‐induced energy transfer (EnT) has resulted in it receiving considerable attention. This Review discusses the most recent advances in visible‐light‐induced EnT reactions.
Zinc–air batteries offer a possible solution for large‐scale energy storage due to their superhigh theoretical energy density, reliable safety, low cost, and long durability. However, their ...widespread application is hindered by low power density. Herein, a multiscale structural engineering of Ni‐doped CoO nanosheets (NSs) for zinc–air batteries with superior high power density/energy density and durability is reported for the first time. In micro‐ and nanoscale, robust 2D architecture together with numerous nanopores inside the nanosheets provides an advantageous micro/nanostructured surface for O2 diffusion and a high electrocatalytic active surface area. In atomic scale, Ni doping significantly enhances the intrinsic oxygen reduction reaction activity per active site. As a result of controlled multiscale structure, the primary zinc–air battery with engineered Ni‐doped CoO NSs electrode shows excellent performance with a record‐high discharge peak power density of 377 mW cm−2, and works stable for >400 h at 5 mA cm−2. Rechargeable zinc–air battery based on Ni‐doped CoO NSs affords an unprecedented small charge–discharge voltage of 0.63 V, outperforming state‐of‐the‐art Pt/C catalyst‐based device. Moreover, it is shown that Ni‐doped CoO NSs assembled into all‐solid‐state coin cells can power 17 light‐emitting diodes and charge an iPhone 7 mobile phone.
A multiscale structure engineering of Ni‐doped CoO nanosheets from micro‐ through nano‐ to atomic scale for high‐power‐density zinc–air batteries is demonstrated. The engineered zinc–air battery based on Ni‐doped CoO nanosheets realizes sufficient mass transport, abundant catalysts active sites, and excellent intrinsic activity simultaneously, affording a record‐high discharge peak power density of 377 mW cm−2.
Hantzsch esters were often previously used as reductants in thermal catalytic hydrogenation reactions. Over the last few decades, Hantzsch esters have proven to be a useful class of electron donors ...and proton sources in photoredox catalyzed processes. Moreover, under photoredox catalytic conditions, alkyl-1,4-dihydropyridines can serve as versatile types of alkylation reagents
via
oxidative fragmentation mechanisms. This minireview highlights the recent advances in the chemistry of Hantzsch esters in photoredox catalyzed organic synthesis, with particular emphasis placed on reaction mechanisms. We hope that this review will inspire further new reaction design and developments with such a class of readily accessible reagents.
This minireview highlights the recent advances in the chemistry of Hantzsch esters in photoredox catalyzed organic synthesis, with particular emphasis placed on reaction mechanisms.
A robust automatic micro-expression recognition system would have broad applications in national safety, police interrogation, and clinical diagnosis. Developing such a system requires high quality ...databases with sufficient training samples which are currently not available. We reviewed the previously developed micro-expression databases and built an improved one (CASME II), with higher temporal resolution (200 fps) and spatial resolution (about 280×340 pixels on facial area). We elicited participants' facial expressions in a well-controlled laboratory environment and proper illumination (such as removing light flickering). Among nearly 3000 facial movements, 247 micro-expressions were selected for the database with action units (AUs) and emotions labeled. For baseline evaluation, LBP-TOP and SVM were employed respectively for feature extraction and classifier with the leave-one-subject-out cross-validation method. The best performance is 63.41% for 5-class classification.
Synthesizing insights from a dynamic capability perspective and social network theory, this study identifies the factors influencing green innovation and examines the relationships between ...influencing factors, green innovation, and performance. This study uses structural equation modeling to test the research hypotheses. The results indicate that dynamic capability, coordination capability, and social reciprocity are significant drivers of green innovation, including green product innovation and green process innovation. Green product and process innovation have positive effects on environmental performance and organizational performance. These findings are relevant to firms in quest of green management and innovation.
COVID-19 is associated with 5.1% mortality. Although the virological, epidemiological, clinical, and management outcome features of COVID-19 patients have been defined rapidly, the inflammatory and ...immune profiles require definition as they influence pathogenesis and clinical expression of COVID-19. Here we show lymphopenia, selective loss of CD4+ T cells, CD8+ T cells and NK cells, excessive T-cell activation and high expression of T-cell inhibitory molecules are more prominent in severe cases than in those with mild disease. CD8+ T cells in patients with severe disease express high levels of cytotoxic molecules. Histochemical studies of lung tissue from one fatality show sub-anatomical distributions of SARS-CoV-2 RNA and massive infiltration of T cells and macrophages. Thus, aberrant activation and dysregulation of CD8+ T cells occur in patients with severe COVID-19 disease, an effect that might be for pathogenesis of SARS-CoV-2 infection and indicate that immune-based targets for therapeutic interventions constitute a promising treatment for severe COVID-19 patients.
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