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A mild and efficient copper-catalyzed radical oxytrifluoromethylation reaction of alkenyl oximes was successfully developed. The method provides a straightforward access to a wide range of CF3-containing isoxazolines in good to excellent yields.

The construction of the Three Gorges Reservoir has had certain effects on the ecological environment of the water and serious phytoplankton blooms have occurred in its tributary embayment. To explore the spatial distribution of nitrogen and phosphorus nutrients and chlorophyll-a in different tributaries of the Three Gorges Reservoir, a water quality study (June 2018) was conducted in the Xiangxi River, Shengnongxi River, and Daning River of the Three Gorges Reservoir. The results showed that the average TN in the three tributaries was 1.86 mg·L

Transition metal-catalyzed enantioselective Sonogashira-type oxidative C(sp3)—C(sp) coupling of unactivated C(sp3)−H bonds with terminal alkynes has remained a prominent challenge. The difficulties mainly stem from the regiocontrol in unactivated C(sp3)—H bond functionalization and the inhibition of readily occurring Glaser homocoupling of terminal alkynes. Here, we report a copper/chiral cinchona alkaloid-based N,N,P-ligand catalyst for asymmetric oxidative cross-coupling of unactivated C(sp3)—H bonds with terminal alkynes in a highly regio-, chemo-, and enantioselective manner. The use of N-fluoroamide as a mild oxidant is essential to site-selectively generate alkyl radical species while efficiently avoiding Glaser homocoupling. This reaction accommodates a range of (hetero)aryl and alkyl alkynes; (hetero)benzylic and propargylic C(sp3)−H bonds are all applicable. This process allows expedient access to chiral alkynyl amides/aldehydes. More importantly, it also provides a versatile tool for the construction of chiral C(sp3)—C(sp), C(sp3)—C(sp2), and C(sp3)—C(sp3) bonds when allied with follow-up transformations., Enantioselective oxidative cross-coupling of unactivated C(sp3)−H bonds and terminal alkynes is challenging. Here, the authors developed a copper/cinchona alkaloid catalyst for the asymmetric Sonogashira-type alkynylation of C(sp3)-H bonds via radical intermediates.

The radical-involved 1,2-difunctionalization of alkenes has developed into a robust tool for preparation of complex organic molecules. Despite significant advances in this area, the catalytic asymmetric version still remains a challenging task mainly due to the difficulty in the stereocontrol of the highly reactive radical intermediates. Recently, owing to the good single-electron transfer ability and coordination with chiral ligands of copper catalysts, remarkable achievements in radical-involved asymmetric alkene difunctionalization have been made via synergistic combination of copper and chiral ligands. This tutorial review highlights the recent progress in copper-catalysed radical-involved asymmetric 1,2-difunctionalization of alkenes and the mechanistic scenarios governing the stereocontrol, with an emphasis on utilization of chiral ligands.

New catalytic systems that contain incompatible catalytic sites were constructed by the in situ polymerization of acidic and basic polymers into metal-organic frameworks, which resulted in highly porous, recyclable, and durable catalytic composites with excellent compartmentalization, so that opposing agents were spatially isolated. These synthesized hybrid catalysts exhibited excellent catalytic activity for one-pot "wolf and lamb" reactions (deacetalization/Knoevenagel or Henry), which was attributed to their unique characteristic of having a locally homogeneous, but globally heterogeneous, structure.

Diverse anti-Markovnikov hydrofunctionalization of alkenols triggered by the addition of S-, P-, and C-centered radicals to alkenes followed by intramolecular 1,5(6)-hydrogen atom transfer (HAT) with remote α-C–H bonds of alcohols has been developed. The strategy simultaneously realized the hydrofunctionalization of alkenes and remote alcohol oxidation. This mild and versatile method allows for direct access to valuable sulfonyl-, phosphonyl-, and malonate-substituted ketones or aldehydes from a wide range of alkenols.

Trifluoromethylation of alkenes has long been the interest of synthetic chemists. It is not only because of the great importance of F-containing compounds, but also on account of the pleasure of cracking the challenges in methodology development in this field. In particular, amino- and azidotrifluoromethylation of alkenes have recently been developing in a fast speed. This digest mainly deals with this advancement in racemic copper- and photocatalyzed amino- and azidotrifluoromethylation of alkenes while giving special highlight on our recent breakthrough on the copper-catalyzed asymmetric aminotrifluoromethylation reaction.

Metal–organic framework (MOF)-based asymmetric heterogeneous catalysts have attracted increasing attention; however, some challenges need to be addressed, such as the rigidity of chiral auxiliary groups within MOFs and the lack of a versatile methodology for the facile construction of chiral MOFs. To address this issue, in this study, a mechanistically distinct approach was developed for heterogenizing linear chiral catalysts in the MOF cavities, rather than the synthetic modification of MOFs. This strategy involves the facile in situ polymerization of pre-impregnated chiral monomers within MOFs, affording the hybrid composites featuring a locally homogeneous and globally heterogeneous structure. The introduced chiral catalytic sites would be flexible in the pores, offering an opportunity to exploit its cooperative effect with the nearby catalytic metal nodes. The advantages of the chiral polymer/MOF composites were clarified by their excellent diastereo- and enantioselectivities and recycling capacity for catalyzing the asymmetric Aldol reaction, which were superior to those of individually heterogeneous and homogeneous catalysts.

Summary Catalytic asymmetric diamination of alkenes is a highly attractive method for creating chiral vicinal diamines, which are ubiquitous in biologically active molecules and versatile ligands as well as organocatalysts. We report the use of O -acylhydroxylamines as dialkylaminyl radical precursors to trigger asymmetric diamination of alkene under Cu(I)/chiral phosphoric acid dual catalysis. This reaction allows for direct alkylamine incorporation and features high enantioselectivity, a broad substrate scope, wide functional-group tolerance, and mild reaction conditions, providing convenient and practical access to a wide range of highly enantio-enriched β-alkylamine-containing pyrrolidines. We have also achieved asymmetric azidoamination of alkenes by using azidoiodinane as an azidyl radical precursor, offering a complementary method for preparing diverse chiral β-amino pyrrolidines. The application of the resultant α-tertiary pyrrolidine-derived diamine was showcased to significantly promote the enantioselectivity of an asymmetric Michael reaction.

(left) received his B.S. degree from Xiamen University in 2003 under the supervision of Prof. Pei-Qiang Huang, and his Ph.D. degree from the Shanghai Institute of Organic Chemistry in 2008 under the supervision of Prof. Guo-Qiang Lin. After postdoctoral research at ­Gakushuin University, Japan with Prof. Takahiko Akiyama, he moved to the University of Texas Southwestern Medical Center, working as a postdoctoral fellow with Prof. John R. Falck and Prof. Chuo Chen. He was appointed as a professor at Soochow University, China in December 2013. He is currently the Head of the Organic Chemistry Department at Soochow University. His current research interests include radical-mediated transformations, in particular radical ­rearrangements, and their applications in the construction of natural products and biologically active compounds. Xin-Yuan Liu (right) obtained his B.S. degree from Anhui Normal University (AHNU) in 2001. He continued his research studies at both the Shanghai Institute of Organic Chemistry (SIOC), CAS and AHNU under the joint supervision of Prof. Dr. Shizheng Zhu and Prof. Dr. Shaowu Wang, obtaining his master’s degree in 2004. After a one-year stint in Prof. Gang Zhao’s laboratory at SIOC, he joined Prof. Dr. Chi-Ming Che’s group at The University of Hong Kong (HKU) and earned his Ph.D. degree in 2010. He subsequently undertook postdoctoral studies in Prof. Che’s group at HKU and in Prof. Carlos F. Barbas III’s group at The Scripps Research Institute. At the end of 2012, he began his independent academic career at the Southern University of Science and Technology (SUSTech) and was promoted to a tenured Full Professor of SUSTech in 2018. His research interests are directed towards the design of novel chiral anionic ligands to solve radical-involved asymmetric reactions.

A general copper-catalyzed C(sp3)−C(sp2) cross-coupling of (hetero)benzyl bromides with the air- and moisture-stable aryl nucleophiles has been developed, providing a facile access to pharmaceutically useful 1,1-di(hetero)arylalkane and 1-aryl-1-heteroarylalkane scaffolds. Critical to the success is the utilization of a proline-based N,N,P-ligand to enhance the reducing capability of copper, thus easily converting benzyl bromides to the corresponding radical species via a single-electron transfer process under ambient conditions. The reaction features a broad substrate scope, covering (hetero)arylboronate esters, oxadiazoles, and benzo[d]oxazoles, as well as primary and secondary (hetero)benzyl bromides with excellent functional group tolerance.

A dual copper/chiral phosphoric acid-catalyzed asymmetric tandem remote C(sp 3 )-H/unactivated alkene functionalization reaction triggered by radical trifluoromethylation of unactivated alkenes for the concomitant construction of C CF 3 and C C bonds was described. This approach provided an efficient method for the synthesis of valuable chiral trifluoromethylated indole derivatives with excellent regio-, chemo-, and good enantioselectivity.

The Cu(I)/phosphoric acid (PA) dual-catalyzed radical aminoperfluoroalkylation and aminodifluoromethylation of alkenes with commercially available fluoroalkylsulfonyl chlorides as the radical source is described. Functionalized α-tertiary pyrrolidines bearing four types of fluoroalkyl groups are obtained with moderate to excellent yields. The introduction of a Cu(I)/phosphoric acid dual catalytic system and the use of silver carbonate as a key additive to inhibit the side hydroamination reaction caused by the in situ generated HCl are crucial for the transformation.

Background and aims The possible role of galectin-3 in acute-on-chronic hepatitis B liver failure (ACHBLF) remains unknown. This study aimed to determine the methylation status of the galectin-3 promoter in patients with ACHBLF and analyze its prognostic value. Methods The methylation status of the galectin-3 promoter in patients with ACHBLF, chronic hepatitis B (CHB) and healthy controls (HCs) was determined by methylation-specific polymerase chain reaction (MSP). The galectin-3 mRNA level in peripheral blood mononuclear cells (PBMCs) was detected using real-time polymerase chain reaction (RT-PCR). Results The methylation frequency of the galectin-3 promoter was significantly higher while galectin-3 mRNA was lower in ACHBLF than in CHB and HCs. Galectin-3 promoter methylation was negatively correlated with the mRNA level in ACHBLF. In addition, ACHBLF patients carrying the methylated promoter showed shorter survival time, higher 3-month mortality, and higher model for end-stage liver disease (MELD) score when compared to ACHBLF patients carrying the unmethylated promoter. Moreover, promoter methylation was a better predictor of 3-week mortality than the MELD score in ACHBLF patients. Conclusion Our results suggest that hypermethylation of the galectin-3 promoter might be an early biomarker for predicting disease severity and prognosis in patients with ACHBLF.

A conceptually novel strategy with achiral pyridine as the ancillary ligand to stabilize high-valent copper species for the first asymmetric radical oxytrifluoromethylation of alkenes with alcohols under CuI /phosphoric acid dual-catalysis has been developed. The transformation features mild reaction conditions, a remarkably broad substrate scope and excellent functional group tolerance, offering an efficient approach to a wide range of trifluoromethyl-substituted tetrahydrofurans bearing an α-tertiary stereocenter with excellent enantioselectivity. Mechanistic studies support the presumed role of the achiral pyridine as a coordinative ligand on copper metal to stabilize the key transient reaction species involved in the asymmetric induction process.

Intramolecular hydrogen atom transfer (HAT) for the remote functionalization of C(sp3)–H bonds has emerged as a powerful strategy, but its asymmetric diversification remains a great challenge because of the requirement of harsh reaction conditions and less enantiotopic discrimination. To overcome this, we described a general and efficient radical protocol for the concomitant functionalization of both alkenes and the remote α-C–H bonds of alcohols or amines via 1,5(6,7)-HAT triggered by the addition of a trifluoromethyl radical to alkenes in a highly controlled site-selective manner. Furthermore, such an approach could be developed for late-stage asymmetric diversification at the remote sp3-hydridized positions of alcohols or amines via a cascade sequence for the facile construction of chiral CF3-containing homoallylic alcohols or secondary amines with good to excellent enantioselectivities. Mechanistic experiments and DFT calculations revealed that 1,5(6,7)-HAT is a kinetically relevant process and provided a rationale for the observed different reactivities between the linear alkenyl alcohol or amine and alkenyl ketone or amide.

Medium-sized and medium-bridged rings are attractive structural motifs in natural products and therapeutic agents. Due to the unfavourable entropic and/or enthalpic factors with these ring systems, their efficient construction remains a formidable challenge. To address this problem, we herein disclose a radical-based approach for diversity-oriented synthesis of various benzannulated carbon- and heteroatom-containing 8–11(14)-membered ketone libraries. This strategy involves 1,4- or 1,5-aryl migration triggered by radical azidation, trifluoromethylation, phosphonylation, sulfonylation, or perfluoroalkylation of unactivated alkenes followed by intramolecular ring expansion. Demonstration of this method as a highly flexible tool for the construction of 37 synthetically challenging medium-sized and macrocyclic ring scaffolds including bridged rings with diverse functionalities and skeletons is highlighted. Some of these products showed potent inhibitory activity against the cancer cell or derivative of human embryonic kidney line in preliminary biological studies. The mechanism of this novel strategy is investigated by control experiments and DFT calculations., Medium-sized ring systems are common in natural products, however their synthesis is challenging, largely due to entropic factors. Here the authors report a radical-based method for the synthesis of medium to large functionalized, carbon or heterocyclic scaffolds.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been reported to kill a wide variety of tumor cells with minimal effects on normal cell. However, renal cell carcinoma (RCC) cells 786-0 and OS-RC-2 were resistant to TRAIL. The present study examines the potential of combining polyphenolic compound resveratrol (RES) with TRAIL. We found that RES can sensitize RCC cells to TRAIL-induced death. Electron microscopy analyses showed that RES plus TRAIL can induce both autophagy and apoptosis in RCC cells. It was proved that the apoptosis is caspase-dependent and the activation of caspase-8, caspase-9, and caspase-3 was involved in this process. Besides, we also found that XIAP expression was significantly inhibited after RES plus TRAIL treatment in RCC cells. Furthermore, a fiber-modified replication-deficient adenovirus Ad5/35-TRAIL was generated to test the synergistic effect of RES and TRAIL in vivo. Our data demonstrated that RES plus Ad5/35-TRAIL significantly inhibited RCC xenograft growth in nude mice. These results suggest the possibility of a new combination therapeutic leading to the improvement of RCC treatment.

Since the pioneering independent reports of Akiyama and Terada, the use of chiral phosphoric acids (CPAs) and derivatives as a versatile tool for asymmetric synthesis with good reactivity, regioselectivity, diastereoselectivity and enantioselectivity has emerged, forming an important part of the implementation of asymmetric counteranion-directed catalysis reported to date. In these achievements, the combination of metals with CPAs has enabled various catalytic modes beyond the scope of typical acid catalysis, such as relay catalysis, ion-pairing catalysis, and binary acid catalysis. The first-row transition metals (Sc–Zn) are considered to be sustainable transition metals and have received a great deal of attention. These naturally abundant metals display excellent Lewis acidity and function as powerful redox catalysts in synthesis involving both one and two-electron transfers. Hence, in this chapter, we summarize recent advances in the development of asymmetric reactions using a combination of first-row transition metals and CPAs. Furthermore, we provide a detailed discussion of the mechanisms involved in order to understand the interaction of the metal/phosphate and the origins of the asymmetric control of the transformations.

The recently identified PPR-E+/NVWA/DYW2 RNA editing complex provides insights into the mechanism of RNA editing in higher plant organelles. However, whether the complex works together with the previously identified editing factors RIPs/MORFs is unclear. In this paper, we identified a maize Smk6 gene, which encodes a mitochondrion-targeted PPR-E+protein with E1 and E2 domains at the C terminus. Loss of Smk6 function affects the C-to-U editing at nad1-740, nad4L-110, nad7-739, and mttB-138,139 sites, impairs mitochondrial activity and blocks embryogenesis and endosperm development. Genetic and molecular analysis indicated that SMK6 is the maize ortholog of the Arabidopsis SLO2, which is a component of the PPR-E+/NVWA/DYW2 editing complex. However, yeast two-hybrid analyses did not detect any interaction between SMK6 and any of the mitochondrion-targeted RIPs/MORFs, suggesting that RIPs/MORFs may not be a component of PPR-E+/NVWA/DYW2 RNA editing complex. Further analyses are required to provide evidence that RIP/MORFs and SMK6 do not physically interact in vivo.

Continued development of the Sonogashira coupling has made it a well established and versatile reaction for the straightforward formation of C-C bonds, forging the carbon skeletons of broadly useful functionalized molecules. However, asymmetric Sonogashira coupling, particularly for C(sp

In mammals, transforming growth factor β-activated kinase 1 (TAK1) and TAK1-binding protein 1 (TAB1) are known as two crucial upstream mediators in the NF-κB signaling pathway. TAK1 interacts with TAB1 to form the TAK1–TAB1 complex, which triggers NF-κB activation through a series of cascade reactions. However, the interaction of TAK1 and TAB1 in grass carp (Ctenopharyngodon idella) and the effects of their interaction on the NF-κB activation remain largely unknown. Here, the transcriptional expression of the CiTAK1 and CiTAB1 genes was firstly detected by RT-qPCR, and both genes showed ubiquitous transcriptional expression in all the examined tissues of healthy grass carp. And the expression levels of both genes were significantly up-regulated in the different tissues of grass carp and C. idella kidney (CIK) cells after stimulation with the potential vaccine antigen of Vibrio mimicus (named OVepis), implying that both proteins are involved in the OVepis-induced immune response. Subsequently, an analysis of the subcellular localization showed that CiTAK1 was a cytoplasmic protein, whereas CiTAB1 was distributed throughout the HEK293T and CIK cells. Co-immunoprecipitation and pull-down assays proved that CiTAK1 could directly interact with CiTAB1 in vitro, which was further confirmed by co-localization assay, where these two proteins co-located in the cytoplasm. Finally, the effects of CiTAK1 and CiTAB1 co-overexpression on the NF-κB activation and transcriptional expression of downstream pro-inflammatory cytokines were investigated. The results showed that the CiNF-κB promoter activity and transcriptional expression levels of IL-1β, IL-8 and TNF-α enhanced significantly in the CiTAK1 and CiTAB1 co-overexpressed cells compared with non-overexpression control or overexpression of CiTAK1 or CiTAB1 alone, especially under rOVepis stimulation. Taken together, the data generated in this study indicate that the direct interaction between CiTAK1 and CiTAB1 might induce CiNF-κB signaling pathway activation in response to vaccine antigen of V. mimicus.

A novel radical 1,2-formylfunctionalization of alkenes involving 1,2(4,5)-formyl migration triggered by addition of various carbon- and heteroatom-centered radicals to alkenes has been developed for the first time, thus providing straightforward access to diverse β-functionalized aldehydes with good efficiency, remarkable selectivity, and excellent functional group tolerance. Analogous transformations mediated by a keto-carbonyl migration have also been effected under similar conditions. This method was used to access ring systems including various benzannulated nine-, ten-, and eleven-membered rings, complex 6-5(6,7)-6(5) fused rings, and bridged rings with diverse functionalities.

Cascade radical cyclization of alkynyl ketones with various carbon- and heteroatom-centered radical precursors via a sequential radical addition/1,5-H radical shift/5-exo-trig/radical cyclization process was realized for the first time. This method provides a strategically novel and step-economical protocol for diversity-oriented synthesis of a wide range of carbocyclic and heterocyclic 6(5)-6-5 fused ring systems with three contiguous stereocenters, including a quaternary carbon in high yields with excellent chemo- and diastereoselectivity.

A chiral-NHC-catalyzed highly diastereo- and enantioselective dearomatizing double Mannich reaction of isoquinolines was developed that provides a powerful and straightforward synthetic route toward substituted tropane derivatives with four contiguous stereocenters. A unique feature of this strategy is the use of readily available isoquinolines to provide two reactive sites for dearomatization, thus opening up an unprecedented approach to tropane derivatives with excellent stereoselectivity. The four-component reactions proceeded smoothly with good results. Thus, the present method is suitable for the diversity-oriented synthesis of useful tropane derivatives with high efficiency.

The asymmetric inverse-electron-demand hetero-Diels–Alder (IEHDA) reactions of imines and dienophiles have emerged as an attractive tool for derivatizing optically active complex azaheterocycles. In comparison, such reactions involving iminium ions remain great challenges because of low association of iminium ions with neutral catalytic centers. To overcome this, we report a metal-phosphate-catalyzed asymmetric tandem hydroamination/formal Povarov reaction of secondary aminoalkynes via a chiral counteranion-controlled iminium ion intermediate strategy. Critical to the success of this challenging strategy was chiral phosphate as an ion pair to achieve counteranion-controlled asymmetric reaction of in situ-generated iminium ions. This method enables a convenient, powerful, and atom-economical access to tetracyclic octahydro-dipyrroloquinoline frameworks bearing multiple contiguous stereogenic centers in good yields with diastereo- and enantioselectivities, from acyclic starting materials, and the catalyst l...

A novel asymmetric radical aminotrifluoromethylation of alkenes has been developed for the first time, providing straightforward access to densely functionalized CF3-containing azaheterocycles bearing an α-tertiary stereocenter with excellent enantioselectivity. The key to success is not only the introduction of a Cu(I)/chiral phosphoric acid dual-catalytic system but also the use of urea with two acidic N-H as both the nucleophile and directing group. The utility of this method is illustrated by facile transformations of the products into other important compounds useful in organic synthesis and medicinal chemistry.

The mechanism of Ni(0)-catalyzed denitrogenative transannulation of 1,2,3-benzotriazin-4(3H)-ones with alkynes to access isoquinolones has been comprehensively studied by a density functional theory (DFT) calculation and control experimental investigation. The results indicate that the transformations proceed via a sequential nitrogen extrusion, carbometalation, Ni–C bond insertion, and reductive elimination process. A frontier molecular orbital (FMO) theory and natural bond orbital (NBO) analysis reveals that the advantages of substituents on chemical reactivity and regioselectivity exist for multiple reasons: (1) Phenyl groups on the N atom of benzotriazinone and/or unsymmetrical alkynes mainly account for the high reactivity and regioselectivity via its electronic effect. (2) The π···π interaction between the phenyl substituent on the alkyne and triazole ring might partially contribute to the high regioselectivity when unsymmetrical alkynes were employed as the substrates. Furthermore, DFT calculations...

A Cu-catalyzed remote sp3 CH/unactivated alkenes functionalization reaction for the concomitant construction of CCF3 and CO bonds was described. An 1,5-H radical transfer involving an sp3 CH bond adjacent to a nitrogen atom and an α-CF3-alkyl radical intermediate derived from unactivated alkenes was observed and demonstrated to proceed via the radical process.

An unprecedented and efficient organic base-catalysed highly chemoselective carbo- and oxytrifluoromethylation of unactivated alkenes with Togni's reagent was developed. The switchable chemoselectivity was tuned by simply changing the organic base catalyst and solvent. Mechanistic studies indicated that a radical cyclization pathway for carbotrifluoromethylation in DMSO and a carbocation pathway for oxytrifluoromethylation in DCE were probably involved.

The Au-catalyzed tandem process of aminoalkynes was explored, providing simple and efficient access to richly functionalized dipyrroloquinoline frameworks with good to excellent yields. The reaction exhibits great efficiency and high atom economy in multiple-bond formation for constructing bioactive azaspiro polycyclic molecules with densely multiple stereogenic centers including quaternary carbons, and shows a broad substrate scope and synthetically important functional group tolerance, which have been illustrated in the first one-step synthesis of incargranine B aglycone and seneciobipyrrolidine (I).

The sediment storage environment in tributaries has been altered by impoundment of water in the Three Gorges Reservoir area, affecting the distribution of phosphorus forms in sediment and processes at the sediment-water interface. Through collection of sediment and overlying water samples in Xiangxi Bay in August 2016 (before impoundment) and October (after impoundment), the distribution characteristics of sedimentary phosphorus and the environmental conditions of storage before and after impoundment were analyzed. Fluxes of PO

Reported is a novel two-step ring-expansion strategy for expeditious synthesis of all ring sizes of synthetically challenging (hetero)aryl-fused medium-sized lactams from readily available 5-8-membered cyclic ketones. This step-economic approach features a remote radical (hetero)aryl migration from C to N under visible-light conditions. Broad substrate scope, good functional-group tolerance, high efficiency, and mild reaction conditions make this procedure very attractive. In addition, this method also provides expedient access to 13-15-membered macrolactams upon an additional one-step manipulation. Mechanistic studies indicate that the reaction involves an amidyl radical and is promoted by acid.

An efficient protocol for oximinotrifluoromethylation of unactivated alkenes was developed via trifluoromethyl radical-induced intramolecular remote oximino migration under mild reaction conditions, providing a wide range of β-trifluoromethylated oximes. Other fluoroalkyl radicals were also applicable for this transformation. This method provided access to synthetically challenging medium-sized ring scaffolds and the 6,7,5-fused lactam skeleton.

There were three rainfall events with different intensity in the Xiangxi Bay (XXB) from May 24 to June 2 in 2016. The factors such as hydrodynamics, water temperature, optical properties, and chlorophyll a concentrations during the rainfall events were analyzed. During the May 27 moderate rain period, the upstream flow of the reservoir bay increased by 1.9 times and the average mixing layer depth in the whole reservoir increased 8.2 m, compared to those before the rainfall event. During the June 1 light rain period, the average mixing layer depth in the whole reservoir increased 1.6 m and the average chlorophyll concentration reduced 2.02 μg·L

This study characterizes the nutrient distribution of the sediment-water system in the Xiangxi River (XXR) during the impoundment of the Three Gorges Reservoir (TGR). In 2016, the research group obtained samples in the Xiangxi River, analyzed the distribution of nitrogen, phosphorus, and O.M. (organic matter) in the sediment-water system, explored the characteristics of "source-sink" between the interstitial water and overlying water, and carried out a cluster analysis for the sampling sites. The results showed that

A copper-catalyzed asymmetric radical oxytrifluoromethylation of alkenyl oxime and Togni's reagent has been successfully developed, thereby providing straightforward access to CF3 -containing isoxazolines bearing α-tertiary stereocenters with excellent yield and enantioselectivity. The key to success is the rational design of cinchona-alkaloid-based sulfonamides as neutral/anionic hybrid ligands to effectively control the stereochemistry in copper-catalyzed reactions involving free alkyl radical species. The utility of this method is illustrated by efficient transformation of the products into useful chiral CF3 -containing 1,3-aminoalcohols.

The first phosphoric acid-catalyzed asymmetric direct arylative reactions of 2-naphthols with quinone derivatives have been developed, providing efficient access to a class of axially chiral biaryldiols in good yields with excellent enantioselectivities under mild reaction conditions. This approach is a highly convergent and functional group tolerant route to the rapid construction of axially chiral compounds from simple, readily available starting materials. The excellent stereocontrol of the process stems from efficient transfer of stereochemical information from the chiral phosphoric acid into the axis chirality of the biaryldiol products. Preliminary results demonstrate that the biaryldiols can act as efficient chiral ligands in asymmetric transformations.

An efficient enantioselective classic three-component Passerini reaction with a broad substrate scope in the presence of a chiral phosphoric acid catalyst has been developed. This represents the general example for classic three-component Passerini reaction with good to excellent enantioselectivies involving aromatic aldehydes and the bulky pivalaldehyde under mild reaction conditions. The feature of this method is highlighted by using a chiral phosphoric acid to activate carboxylic acid, aldehyde, and isocyanide for the facile construction of widely useful complex compounds.

The first highly diastereo- and enantioselective multicomponent reaction of diazooxindoles, nitrosoarenes, and nitroalkenes using a newly developed hydrogen-bond catalyst has been successfully developed for the efficient construction of a series of spirooxindole derivatives with excellent functional-group tolerance. Spirooxindoles are formed in excellent yields and stereoselectivities, and the method represents an unprecedented approach for trapping the active intermediate with a nitroalkene to form biologically important compounds having three contiguous stereogenic centers with excellent asymmetric induction.

The first Ni(0)/bis(oxazoline)-catalyzed asymmetric denitrogenative transannulation of 1,2,3-benzotriazin-4(3H)-ones with bulky internal alkynes to form novel axially chiral isoquinolones in an atroposelective manner has been developed. This method provides direct asymmetric access to axially chiral isoquinolones with excellent functional-group tolerance in excellent yields and stereoselectivities from readily available starting materials under mild reaction conditions. These axially chiral isoquinolones exhibit high cytotoxicity against a number of human cancer cell lines. DFT calculations reveal the nature of the transition state in the key annulation step.

The first highly enantioselective Brønsted acid catalyzed intramolecular hydroamination of alkenes enables the efficient construction of a series of chiral (spirocyclic) pyrrolidines with an α-tetrasubstituted carbon stereocenter with excellent functional group tolerance. A unique feature of this strategy is the use of a thiourea group acting as both the activating and the directing group through cooperative multiple hydrogen bonding with a Brønsted acid and the double bond. The utility of this method is highlighted by the facile construction of chiral synthetic intermediates and important structural motifs that are widely found in organic synthesis.

The first unprecedented one-pot domino strategy toward diverse CF3-containing γ-lactam and spirobenzofuranone-lactam scaffolds of antibacterial armeniaspirole from readily available acyclic precursors was developed. The key point of this transformation was the concurrent incorporation of CF3 and azide into the alkene and remote carbonyl α-C–H position via carbonyl-stabilized radical intermediate triggered by alkene trifluoromethylation via a 1,5-H shift in a highly controlled site-selective manner. Furthermore, gram-scale synthesis and synthetic applicability of these compounds proved suitable.

A metal-free direct remote C-H functionalization triggered by radical trifluoromethylation of alkenes was explored, realizing highly selective 1,6-difunctionalization of alkenes toward valuable trifluoromethyl α-hydroxycarbonyl compounds. Furthermore, a metal-free direct intermolecular regioselective 1,2-oxytrifluoromethylation of alkenes is also disclosed. With Togni's reagent as both the CF3 source and oxidant, the reaction exhibits a broad substrate scope with excellent functionality tolerance under mild metal-free conditions, thus showing great potential for synthetic utility.