A multicomponent reaction of 2-alkynylbenzaldehyde, sulfonohydrazide, and tertiary amine is discovered, which generates the unexpected H-pyrazolo5,1-aisoquinolines in good yields under mild ...conditions. In the reaction process, silver(I)-catalyzed intramolecular cyclization and copper(II)-catalyzed oxidation of an aliphatic C-H bond of tertiary amine in air are involved.
N‐arylcarbazole structures are important because of their prevalence in natural products and functional OLED materials. C−H amination of arenes has been widely recognized as the most efficient ...approach to access these structures. Conventional strategies involving transition‐metal catalysts suffer from confined substrate generality and the requirement of exogenous oxidants. Organocatalytic enantioselective C–N chiral axis construction remains elusive. Presented here is the first organocatalytic strategy for the synthesis of novel axially chiral N‐arylcarbazole frameworks by the assembly of azonaphthalenes and carbazoles. This reaction accommodates broad substrate scope and gives atropisomeric N‐arylcarbazoles in good yields with excellent enantiocontrol. This approach not only offers an alternative to metal‐catalyzed C–N cross‐coupling, but also brings about opportunities for the exploitation of structurally diverse N‐aryl atropisomers and OLED materials.
In the frame: Presented here is the first organocatalytic strategy for the synthesis of novel axially chiral N‐arylcarbazole frameworks by the assembly of azonaphthalenes and carbazoles. This reaction accommodates broad substrate scope and gives atropisomeric N‐arylcarbazoles in good yields with excellent enantiocontrol. This approach offers opportunities for the exploitation of structurally diverse N‐aryl atropisomers and OLED materials. CPA=chiral phosphoric acid.
From the viewpoint of synthetic accessibility and functional group compatibility, photoredox-catalyzed sulfur dioxide insertion strategy enables in situ generation of functionalized sulfonyl radicals ...from easily accessible starting materials under mild conditions, thereby conferring broader application potential. Here we present two complementary photoinduced sulfur dioxide insertion systems to trigger radical asymmetric Truce-Smiles rearrangements for preparing a variety of chiral sulfones that bear a quaternary carbon stereocenter. This protocol features broad substrate scope and excellent stereospecificity. Aside from scalability, the introduction of a quaternary carbon stereocenter at position β to bioactive molecule-derived sulfones further demonstrates the practicality and potential of this methodology.
Presented here is a class of novel axially chiral aryl‐p‐quinones as platform molecules for the preparation of non‐C2 symmetric biaryldiols. Two sets of aryl‐p‐quinone frameworks were synthesized ...with remarkable enantiocontrol by means of chiral phosphoric acid catalyzed enantioselective arylation of p‐quinones by central‐to‐axial chirality conversion. These aryl‐p‐quinones were then used to access a wide spectrum of highly functionalized non‐C2 symmetric biaryldiols with excellent retention of the enantiopurity.
A class of atropisomeric aryl‐p‐quinones were efficiently assembled by means of chiral phosphoric acid catalyzed enantioselective arylation of p‐quinones through a central‐to‐axial chirality transfer process. This novel axially chiral framework served as a platform for diversity‐oriented synthesis of a wide range of highly functionalized non‐C2 symmetric biaryldiols with preservation of the chirality.
The well‐defined conformational properties of axially chiral compounds bring extraordinary values to an assortment of bioactive molecules, advanced materials, organocatalysts as well as chiral ...ligands in asymmetric transformations. The demonstrated usefulness and untapped potential of axially chiral structural motifs stimulate increasing efforts to develop novel and efficient approaches for their preparation. In this regard, the chiral phosphoric acids broadly used in asymmetric Brønsted acid catalysis have shown high relevance for atroposelective synthesis as well. Our strong interest in reaction chemistry of atropisomers has established a rewarding research programme in our group. The course of studies will be recounted in this Account, with discussion focused on the use of chiral phosphoric acids to catalyze construction of several key axially chiral structures such as BINAM, BINOL, NOBIN, arylquinones, SPINOL, arylpyrrole analogues and axially chiral alkenes.
What is the most favorite and original chemistry developed in your research group?
Organocatalytic asymmetric arene C—H functionalization.
What is the most important personality for scientific research?
Persistence, smart thinking.
What are your hobbies?
Playing basketball, playing card.
What's your favorite book(s)?
The Ordinary World by the famous Chinese writer Yao Lu.
Who influences you mostly in your life?
My parents and my supervisors Prof. Guofu Zhong and Carlos F. Barbas III.
How do you supervise your students?
I advise my students to work smartly and work hard.
The well‐defined conformational properties of axially chiral compounds bring extraordinary values to an assortment of bioactive molecules, advanced materials, organocatalysts as well as chiral ligands in asymmetric transformations. The demonstrated usefulness and untapped potential of axially chiral structural motifs stimulate increasing efforts to develop novel and efficient approaches for their preparation. In this regard, the chiral phosphoric acids broadly used in asymmetric Brønsted acid catalysis have shown high relevance for atroposelective synthesis as well. Our strong interest in reaction chemistry of atropisomers has established a rewarding research programme in our group. The course of studies will be recounted in this account, with discussion focused on the use of chiral phosphoric acids to catalyze construction of several key axially chiral structures such as BINAM, BINOL, NOBIN, arylquinones, SPINOL, arylpyrrole analogues and axially chiral alkenes.
In recent years, visible light driven enantioselective chemical transformations have emerged as new additions to the toolkit of synthetic chemists to accomplish more efficient assembly of chiral ...molecules. Nonetheless, implementing precise stereocontrol on photoinduced intermolecular radical coupling process remains arduous. Recent studies unveil the underexplored competence of chiral phosphoric acid for this class of asymmetric photoredox reactions, endowed by its capability as a bifunctional H‐bonding catalyst for synchronous interaction with radical intermediate and substrate while channeling the cross‐coupling in a highly enantioselective manner. This paper highlights the recent advances, future outlook as well as the prospective challenges in this research area.
In recent years, visible light driven enantioselective chemical transformations have emerged as new additions to the toolkit of synthetic chemists to accomplish more efficient assembly of chiral molecules. Nonetheless, implementing precise stereocontrol on photoinduced intermolecular radical coupling process remains arduous. Recent studies unveil the underexplored competence of chiral phosphoric acid for this class of asymmetric photoredox reactions, endowed by its capability as a bifunctional H‐bonding catalyst for synchronous interaction with radical intermediate and substrate while channeling the cross‐coupling in a highly enantioselective manner. This paper highlights the recent advances, future outlook as well as the prospective challenges in this research area.
Fine particulate matter (PM2.5) has been widely regarded as an important environmental risk factor that has widely influenced health of both animals and humans. Lung injury is the main cause of PM2.5 ...affecting respiratory tract health. Gut microbiota participates in the development of lung injury in many pathological processes. However, there is still unknown the specific effects of PM2.5 on the gut-lung axis in broilers. Thus, we conducted a broiler model based on 3-wk-old male Arbor Acres broiler to explore the underlying mechanism. Our results showed that PM2.5 exposure triggered TLR4 signaling pathway and induced the increase of IL-6, IFN-γ, TNF-α expression as well as the decrease of IL-10 expression in the lung. Inhaled PM2.5 exposure significantly altered the gut microbiota diversity and community. Specifically, PM2.5 exposure decreased α diversity and altered β diversity of gut microbiota, and reduced the abundance of DTU089, Oscillospirales, Staphylococcus, and increased the Escherichia-Shigella abundance, leading to the increase of gut-derived lipopolysaccharides (LPS). Moreover, PM2.5 significantly disrupted the intestinal epithelial barrier by reducing the expression of muc2 and claudin-1 to increase intestinal permeability, which possibly facilitated the LPS translocation into the blood. Spearman analysis revealed that gut microbiota dysbiosis was positively related to TLR4, TNF-α, and IFN-γ expression in the lung. In summary, our results showed that PM2.5 exposure induced lung injury by causing inflammation and triggering TLR4 signaling pathway, and also induced gut microbiota dysbiosis resulting in the overproduction of gut-derived LPS. And gut microbiota dysbiosis may be associated with lung injury. The above results provide basis data to comprehend the potential role of gut microbiota dysbiosis in the lung injury as well as providing a new regulatory target for alleviating lung injury associated with environmental pollutants.
Substance abuse in young adults is a public health issue with costs to the individual and society. There is mounting evidence that the increased uses of mHealth approaches have promise as a way to ...facilitate reductions in substance use. This systematic review evaluated the recent body of research on mHealth-based interventions for substance use, with aims of (a) examining the functionality and effectiveness of these interventions, (b) evaluating the available research on the effectiveness of these interventions for substance use, and (c) evaluating the design, methodology, results, theoretical grounding, limitations, and implications of each study. We identified eligible studies by searching electronic databases using Boolean methods. The reviewed studies (N = 12) indicated that that a wide range of Internet-based, text messaging, and smartphone application interventions have been developed to address substance use. Interventions had an assortment of features; participants in each study highlighted the ease and convenience of the interventions; and the majority of studies provided support for the efficacy of mHealth in reducing substance use. Mobile technology is a promising tool for reducing substance use and warrants further development. Future practice including the use of mHealth interventions can be an integral part of reducing substance use.
Achieving coastal and shallow-water bathymetry is essential for understanding the marine environment and for coastal management. Bathymetric data in shallow sea areas can currently be obtained using ...SDB (satellite-derived bathymetry) with multispectral satellites based on depth inversion models. In situ bathymetric data are crucial for validating empirical models but are currently limited in remote and unapproachable areas. In this paper, instead of using the measured water depth data, ICESat-2 (Ice, Cloud, and Land Elevation Satellite-2) ATL03 bathymetric points at different acquisition dates and multispectral imagery from Sentinel-2/GeoEye-1 were used to train and evaluate water depth inversion empirical models in two study regions: Shanhu Island in the South China Sea, and Heron Island in the Great Barrier Reef (GBR) in Australia. However, different sediment types also influenced the SDB results. Therefore, three types of sediments (sand, reef, and coral/algae) were analyzed for Heron Island, and four types of sediments (sand, reef, rubble and coral/algae) were analyzed for Shanhu Island. The results show that accuracy generally improved when sediment classification information was considered in both study areas. For Heron Island, the sand sediments showed the best performance in both models compared to the other sediments, with mean R2 and RMSE values of 0.90 and 1.52 m, respectively, representing a 5.6% improvement of the latter metric. For Shanhu Island, the rubble sediments showed the best accuracy in both models, and the average R2 and RMSE values were 0.97 and 0.65 m, respectively, indicating an RMSE improvement of 15.5%. Finally, bathymetric maps were generated in two regions based on the sediment classification results.
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