Publications by authors named "Bingxian Liu"

26 Publications

  • Page 1 of 1

Rhodium(III)-catalyzed asymmetric [4+1] spiroannulations of -pivaloyl oximes with α-diazo compounds.

Chem Commun (Camb) 2021 Jul 29. Epub 2021 Jul 29.

Henan Key Laboratory of Organic Functional Molecule and Drug Innovation, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China. and Institute of Molecular Science and Engineering, Institute of Frontier and Interdisciplinary Sciences, Shandong University, Qingdao, China and School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.

Chiral RhIII catalysts can catalyze the asymmetric [4+1] spiroannulation of O-pivaloyl oximes with α-diazo homophthalimides under redox-neutral and acid/base-neutral conditions, leading to formation of chiral spirocyclic imines as a result of C-H activation and N-O cleavage. The reaction proceeded with high efficiency and features broad substrate scope, mild reaction conditions, and high to excellent enantioselectivities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d1cc02888jDOI Listing
July 2021

Exposure to the herbicide butachlor activates hepatic stress signals and disturbs lipid metabolism in mice.

Chemosphere 2021 Jun 15;283:131226. Epub 2021 Jun 15.

College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China. Electronic address:

Butachlor is a systemic herbicide widely applied on wheat, rice, beans, and different other crops, and is frequently detected in groundwater, surface water, and soil. Therefore, it is necessary to investigate the potential adverse health risks and the underlying mechanisms of hepatotoxicity caused by exposure to butachlor in invertebrates, other nontarget animals, and public health. For this reason, a total of 20 mice were obtained and randomly divided into two groups. The experimental mice in one group were exposed to butachlor (8 mg/kg) and the mice in control group received normal saline. The liver tissues were obtained from each mice at day 21 of the trial. Results indicated that exposure to butachlor induced hepatotoxicity in terms of swelling of hepatocyte, disorders in the arrangement of hepatic cells, increased concentrations of different serum enzymes such as alkaline phosphate (ALP) and aspartate aminotransferase (AST). The results on the mechanisms of liver toxicity indicated that butachlor induced overexpression of Apaf-1, Bax, Caspase-3, Caspase-9, Cyt-c, p53, Beclin-1, ATG-5, and LC3, whereas decreases the expression of Bcl-2 and p62 suggesting abnormal processes of apoptosis and autophagy. Results on different metabolites (61 differential metabolites) revealed upregulation of PE and LysoPC, whereas downregulation of SM caused by butachlor exposure in mice led to the disruption of glycerophospholipids and lipid metabolism in the liver. The results of our experimental research indicated that butachlor induces hepatotoxic effects through disruption of lipid metabolism, abnormal mechanisms of autophagy, and apoptosis that provides new insights into the elucidation of the mechanisms of hepatotoxicity in mice induced by butachlor.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemosphere.2021.131226DOI Listing
June 2021

Long-term copper exposure promotes apoptosis and autophagy by inducing oxidative stress in pig testis.

Environ Sci Pollut Res Int 2021 Jun 15. Epub 2021 Jun 15.

College of Veterinary, South China Agricultural University, Guangzhou, 510642, China.

Copper (Cu) is a heavy metal which is being used widely in the industry and agriculture. However, the overuse of Cu makes it a common environmental pollutant. In order to investigate the testicular toxicity of Cu, the pigs were divided into three groups and were given Cu at 10 (control), 125, and 250 mg/kg body weight, respectively. The feeding period was 80 days. Serum hormone results showed that Cu exposure decreased the concentrations of follicular stimulating hormone (FSH) and luteinizing hormone (LH) and increased the concentration of thyroxine (T4). Meanwhile, Cu exposure upregulated the expression of Cu transporter mRNA (Slc31a1, ATP7A, and ATP7B) in the testis, leading to increase in testicular Cu and led to spermatogenesis disorder. The Cu exposure led to an increased expression of antioxidant-related mRNA (Gpx4, TRX, HO-1, SOD1, SOD2, SOD3, CAT), along with increase in the MDA concentration in the testis. In LG group, the ROS in the testis was significantly increased. Furthermore, the apoptotic-related mRNA (Caspase3, Caspase8, Caspase9, Bax, Cytc, Bak1, APAF1, p53) and protein (Active Caspase3) and the autophagy-related mRNA (Beclin1, ATG5, LC3, and LC3B) expression increased after Cu exposure. The mitochondrial membrane potential in the testicular tissue decreased, while the number of apoptotic cells increased, as a result of oxidative stress. Overall, our study indicated that the Cu exposure promotes testicular apoptosis and autophagy by mediating oxidative stress, which is considered as the key mechanism causing testicular degeneration as well as dysfunction.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11356-021-14853-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8203493PMC
June 2021

Mosquito-borne infectious diseases in China, 2019.

Travel Med Infect Dis 2021 May-Jun;41:102050. Epub 2021 Apr 2.

College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.tmaid.2021.102050DOI Listing
July 2021

Environmental fluoride exposure disrupts the intestinal structure and gut microbial composition in ducks.

Chemosphere 2021 Aug 19;277:130222. Epub 2021 Mar 19.

College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China. Electronic address:

Fluorine (F) and its compounds produced from industrial production and coal combustion can cause air, water and soil contamination, which can accumulate in animals, plants and humans via food chain threatening public health. Fluoride exposure affects liver, kidney, gastrointestinal and reproductive system in humans and animals. Literature regarding fluoride influence on intestinal structure and microbiota composition in ducks is scarce. This study was designed to investigate these effects by using simple and electron microscopy and 16S rRNA sequencing techniques. Results indicated an impaired structure with reduced relative distribution of goblet cells in the fluoride exposed group. Moreover, the gut microbiota showed a significant decrease in alpha diversity. Proteobacteria, Firmicutes and Bacteroidetes were the most abundant phyla in both control and fluoride-exposed groups. Specifically, fluoride exposure resulted in a significant decrease in the relative abundance of 9 bacterial phyla and 15 bacterial genera. Among them, 4 phyla (Latescibacteria, Dependentiae, Zixibacteria and Fibrobacteres) and 4 genera (Thauera, Hydrogenophaga, Reyranella and Arenimonas) weren't even detectable in the gut microbiota of the ducks. In summary, higher fluoride exposure can significantly damage the intestinal structure and gut microbial composition in ducks.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemosphere.2021.130222DOI Listing
August 2021

Microbiome Analysis Reveals the Attenuation Effect of From Yaks on Diarrhea Modulation of Gut Microbiota.

Front Cell Infect Microbiol 2020 16;10:610781. Epub 2021 Feb 16.

Animal Science College, Tibet Agriculture & Animal Husbandry University, Linzhi, China.

Domestic yaks () are indigenous to the Tibetan Plateau and display a high diarrhea rate due to poor habitat and husbandry conditions. has been shown to exert beneficial effects as antimicrobial, growth promotion, and gut microbiota in humans and/or murine models, but the relevant data regarding isolated from yaks was unavailable. Therefore, this study aimed to investigate the effects of from yaks on the intestinal microbial community in a mouse model and determine whether supplementation contributed in alleviating diarrhea by modulating gut microbiota. A total of 12 ileac samples from four groups were collected for 16S rRNA gene amplicon sequencing of V3-V4 region. Results revealed that although supplementation did not change the diversity of gut microbiota in mice, the proportion of some intestinal microbiota significantly changed. Specifically, the proportion of and in the treated-group (L-group) were increased as compared to control group (C-group), whereas , , , , , , , , , and were significantly decreased in the L-group. In contrast, () infection significantly decreased the proportion of beneficial bacteria such as , , , and , while loads of pathogenic bacteria significantly increased including and . Interestingly, administration could ameliorate the microbial community structure of -induced diarrheal mice by reducing the relative abundance of pathogenic bacteria such as , , , , , , and . Results in this study revealed that supplementation not only improved the gut microbiota but also alleviated diarrhea in mice, which may be mediated by modulating the composition and function of gut microbiota. Moreover, this study is expected to provide a new theoretical basis for the establishment of a preventive and treatment system for diarrhea in yaks.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fcimb.2020.610781DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7920975PMC
June 2021

Acetyl-L-Carnitine Induces Autophagy to Promote Mouse Spermatogonia Cell Recovery after Heat Stress Damage.

Biomed Res Int 2021 18;2021:8871328. Epub 2021 Jan 18.

College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China.

Acetyl-L-carnitine (ALC) is an effective substrate for mitochondrial energy metabolism and is known to prevent neurodegeneration and attenuate heavy metal-induced injury. In this study, we investigated the function of ALC in the recovery of mouse spermatogonia cells (GC-1 cells) after heat stress (HS). The cells were randomly divided into three groups: control group, HS group (incubated at 42°C for 90 min), and HS + ALC group (treatment of 150 M ALC after incubated at 42°C for 90 min). After heat stress, all of the cells were recovered at 37°C for 6 h. In this study, the content of intracellular lactate dehydrogenase (LDH) in the cell supernatant and the malondialdehyde (MDA) levels, catalase (CAT) levels, and total antioxidant capacity (T-AOC) were significantly increased in the HS group compared to the CON group. In addition, the mitochondrial membrane potential (MMP) was markedly decreased, while the apoptosis rate and the expression of apoptosis-related genes (Bcl-2, Bax, and caspase3) were significantly increased in the HS group compared to the CON group. Furthermore, the number of autophagosomes and the expression of autophagy-related genes (Atg5, Beclin1, and LC3II) and protein levels of p62 were increased, but the expression of LAMP1 was decreased in the HS group compared to the CON group. However, treatment with ALC remarkably improved cell survival and decreased cell oxidative stress. It was unexpected that levels of autophagy were markedly increased in the HS + ALC group compared to the HS group. Taken together, our present study evidenced that ALC could alleviate oxidative stress and improve the level of autophagy to accelerate the recovery of GC-1 cells after heat stress.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2021/8871328DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7837762PMC
May 2021

The hepatotoxicity of altrazine exposure in mice involves the intestinal microbiota.

Chemosphere 2021 Jun 11;272:129572. Epub 2021 Jan 11.

College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China. Electronic address:

Atrazine (ATR), a bio accumulative herbicide is frequently used in agriculture to control unwanted weeds. Due to continuous application, atrazine persists in the environment and causes deleterious impacts including neurotoxicity, hepatotoxicity, and gut microbiota disorders. Therefore, this study for the first time reports the variation in the gut microbiota, induction of process of apoptosis and autophagy in mice induced by ATR. Results indicated that TUNEL-positive hepatocytes suggestive of apoptosis were increased in livers of different experimental mice. Results on metabolic analysis in liver tissues indicated an overall change in seventy-six metabolites particularly Uridine 5'-diphosphate, Propenoylcarnitine and Chinenoside V resulting in generation of energy-related metabolic disorders and imbalance of oxidation/autoxidation status. Results on gut microbiome inquisition showed that ATR changed the richness and diversity of gut microbiota of mice and number of Firmicutes. Moreover, results also revealed that ATR induced apoptosis via disruption of apoptotic (Bax, Bcl2, and Casp3) and autophagy (LC3/Map1lc3a, Beclin 1/Becn1 and P62/Sqstm1) genes. Results of our experimental study confirmed that changes in gut microbiota play a significant role in process of gut immune regulation and inflammation via different metabolites. In conclusion, the findings of our study provide a new idea for the involvement of mechanisms of detoxification in liver and inquisition of gut microbiota plays crucial role in regulation of physiological activities through liver-gut axis to mitigate toxic effects in animals.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemosphere.2021.129572DOI Listing
June 2021

Rhodium-Catalyzed Enantioselective Synthesis of β-Amino Alcohols via Desymmetrization of gem-Dimethyl Groups.

Angew Chem Int Ed Engl 2021 04 1;60(15):8396-8400. Epub 2021 Mar 1.

Henan Key Laboratory of Organic Functional Molecule and Drug Innovation, NMPA Key Laboratory for Research and Evaluation of Innovative Drug, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, 453007, China.

Desymmetrization of gem-dimethyl groups en route to the rhodium(III)-catalyzed enantioselective sp C-H amidation is reported. Synthetically important β-amino alcohol derivatives were accessed in moderate to good yields and high enantioselectivity. The high enantioselectivity is enabled by an appropriate oxime directing group, sterically biased gem-groups in the C-H substrate, and high reactivity of the amidating reagent.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/anie.202014080DOI Listing
April 2021

Rhodium-Catalyzed Atroposelective Construction of Indoles via C-H Bond Activation.

Angew Chem Int Ed Engl 2021 04 26;60(15):8391-8395. Epub 2021 Feb 26.

School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, 453007, China.

Reported herein is the rhodium(III)-catalyzed C-H activation of anilines bearing an N-isoquinolyl directing group for oxidative [3+2] annulation with four classes of internal alkynes, leading to atroposelective indole synthesis via dynamic kinetic annulation with C-N reductive elimination constituting the stereo-determining step. This reaction proceeds under mild conditions with high regio- and enantioselectivity and functional group compatibility.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/anie.202012932DOI Listing
April 2021

Rh(iii)-Catalyzed acylation of heteroarenes with cyclobutenones via C-H/C-C bond activation.

Chem Commun (Camb) 2020 Dec 7;56(100):15631-15634. Epub 2020 Dec 7.

Henan Key Laboratory of Organic Functional Molecule and Drug Innovation, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China.

Rhodium(iii)-catalyzed C-H acylation of heteroarenes has been realized using cyclobutenones as an acylating reagent. This coupling proceeded via integration of C-H activation of heteroarenes and C-C cleavage of cyclobutenones. The reaction features excellent regio/chemoselectivity leading to versatile chalcones with exclusive E-selectivity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0cc05965jDOI Listing
December 2020

Iodonium Ylides as Carbene Precursors in Rh(III)-Catalyzed C-H Activation.

Org Lett 2020 10 9;22(19):7475-7479. Epub 2020 Sep 9.

Henan Key Laboratory of Organic Functional Molecule and Drug Innovation, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China.

The rhodium(III)-catalyzed coupling of C-H substrates with iodonium ylides has been realized for the efficient synthesis of diverse cyclic skeletons, where the iodonium ylides have been identified as efficient and outstanding carbene precursors. The reaction systems are applicable to both sp and sp C-H substrates under mild and redox-neutral conditions. The catalyst loading can be as low as 0.5 mol % in a gram-scale reaction. Representative products exhibit cytotoxicity toward human cancer cells at nanomolar levels.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.orglett.0c02618DOI Listing
October 2020

Rh(III)-Catalyzed Coupling of Acrylic Acids and Ynenones via Olefinic C-H Activation and Michael Addition.

Org Lett 2020 01 30;22(2):438-442. Epub 2019 Dec 30.

Henan Key Laboratory of Organic Functional Molecule and Drug Innovation, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering , Henan Normal University , Xinxiang 453007 , China.

Rh(III)-catalyzed coupling between acrylic acids and yndienones has been realized for the synthesis of -hydrobenzofuranone. The reaction proceeded in excellent regio- and stereoselectivity under mild and redox-neutral conditions via a sequence of carboxylic acid-directed olefinic C-H activation, alkyne insertion, and Michael addition. Representative products were found to exhibit cytotoxicity toward the A549 cancer cell line at micromolar levels.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.orglett.9b04191DOI Listing
January 2020

Toxic effects of arsenic trioxide on spermatogonia are associated with oxidative stress, mitochondrial dysfunction, autophagy and metabolomic alterations.

Ecotoxicol Environ Saf 2020 Mar 14;190:110063. Epub 2019 Dec 14.

College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China. Electronic address:

Arsenic is a toxic metalloid that can cause male reproductive malfunctions and is widely distributed in the environment. The aim of this study was to investigate the cytotoxicity of arsenic trioxide (ATO) induced GC-1 spermatogonial (spg) cells. Our results found that ATO increased the levels of catalase (CAT) and malonaldehyde (MDA) and reactive oxygen species (ROS), while decreasing glutathione (GSH) and the total antioxidant capacity (T-AOC). Therefore, ATO triggered oxidative stress in GC-1 spg cells. In addition, ATO also caused severe mitochondrial dysfunction that included an increase in residual oxygen consumption (ROX), and decreased the routine respiration, maximal and ATP-linked respiration (ATP-L-R), as well as spare respiratory capacity (SRC), and respiratory control rate (RCR); ATO also damaged the mitochondrial structure, including mitochondrial cristae disordered and dissolved, mitochondrial vacuolar degeneration. Moreover, degradation of p62, LC3 conversion, increasing the number of acidic vesicle organelles (AVOs) and autophagosomes and autolysosomes are demonstrated that the cytotoxicity of ATO may be associated with autophagy. Meanwhile, the metabolomics analysis results showed that 20 metabolites (10 increased and 10 decreased) were significantly altered with the ATO exposure, suggesting that maybe there are the perturbations in amino acid metabolism, lipid metabolism, glycan biosynthesis and metabolism, metabolism of cofactors and vitamins. We concluded that ATO was toxic to GC-1 spg cells via inducing oxidative stress, mitochondrial dysfunction and autophagy as well as the disruption of normal metabolism. This study will aid our understanding of the mechanisms behind ATO-induced spermatogenic toxicity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ecoenv.2019.110063DOI Listing
March 2020

Mn(i)-Catalyzed nucleophilic addition/ring expansion via C-H activation and C-C cleavage.

Chem Commun (Camb) 2019 Sep 21;55(72):10764-10767. Epub 2019 Aug 21.

Henan Key Laboratory of Organic Functional Molecule and Drug Innovation, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China. and School of Chemistry and Chemical Engineering, Shaanxi Normal University (SNNU), Xi'an 710062, China.

Mn(i)-Catalyzed synthesis of seven- or eight-membered carbocycles is disclosed via C-H activation of heteroarenes and coupling with alkyne-functionalized 1,3-cyclopentadiones or 1,3-cyclohexadiones. This n to n + 2 (n = 5, 6) ring expansion reaction proceeded via a C-H alkenylation/carbonyl addition/retro-Aldol cascade. Structurally diverse mid-sized carbocycles were constructed via cleavage of both C-H and C-C bonds in a single operation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c9cc05973cDOI Listing
September 2019

Rhodium(iii)-catalyzed diverse [4 + 1] annulation of arenes with 1,3-enynes sp/sp C-H activation and 1,4-rhodium migration.

Chem Sci 2019 Apr 26;10(14):3987-3993. Epub 2019 Feb 26.

Henan Key Laboratory of Organic Functional Molecule and Drug Innovation , School of Chemistry and Chemical Engineering , Henan Normal University , Xinxiang 453007 , China.

Nitrogen-rich heterocyclic compounds have a profound impact on human health. Despite the numerous synthetic methods, diversified, step-economic, and general synthesis of heterocycles remains limited. C-H bond functionalization catalyzed by rhodium(iii) cyclopentadienyls has proven to be a powerful strategy in the synthesis of diversified heterocycles. Herein we describe rhodium(iii)-catalyzed sp and sp C-H activation-oxidative annulations between aromatic substrates and 1,3-enynes, where alkenyl-to-allyl 1,4-rhodium(iii) migration enabled the generation of electrophilic rhodium(iii) π-allyls remote C-H functionalization. Subsequent nucleophilic trapping of these species by various sp-hybridized N-nucleophiles delivered three classes (external salts, inner salts, and neutral azacycles) of five-membered azacycles bearing a tetrasubstituted saturated carbon center, as a result of [4 + 1] annulation with the alkyne being a one-carbon synthon. All the reactions proceeded under relatively mild conditions with broad substrate scope, high efficiency, and excellent regioselectivity. The synthetic applications of this protocol have also been demonstrated, and experimental studies have been performed to support the proposed mechanism.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c9sc00545eDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6457175PMC
April 2019

Ag(I)-Catalyzed Nucleophilic Addition and Friedel-Crafts Alkylation between α-Oxoketene Dithioacetals and Propargyl Carbonates.

Org Lett 2018 12 5;20(24):7775-7778. Epub 2018 Dec 5.

Henan Key Laboratory of Organic Functional Molecule and Drug Innovation, School of Chemistry and Chemical Engineering , Henan Normal University , Xinxiang 453007 , China.

Silver-catalyzed nucleophilic addition and intramolecular Friedel-Crafts alkylation between α-oxoketene dithioacetals and tertiary propargylic carbonates have been realized. The reactions proceeded in moderate to good yields with broad substrate scope, providing a straightforward method for the synthesis of substituted indenes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.orglett.8b03180DOI Listing
December 2018

Rh(III)-Catalyzed C-C Coupling of Diverse Arenes and 4-Acyl-1-sulfonyltriazoles via C-H Activation.

Org Lett 2018 08 2;20(16):4946-4949. Epub 2018 Aug 2.

Henan Key Laboratory of Organic Functional Molecule and Drug Innovation, School of Chemistry and Chemical Engineering , Henan Normal University , Xinxiang 453007 , China.

4-Acyl-1-sulfonyltriazoles act as versatile carbene reagents in Cp*Rh(III)-catalyzed ortho-selective coupling with arenes via C-H activation. The coupling led to olefination with possible cyclization, depending on the nature of the arene.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.orglett.8b02078DOI Listing
August 2018

Construction of (Dihydro)naphtho[1,8- bc]pyrans via Rh(III)-Catalyzed Twofold C-H Activation of Benzoylacetonitriles.

Org Lett 2018 04 2;20(8):2160-2163. Epub 2018 Apr 2.

Henan Key Laboratory of Organic Functional Molecule and Drug Innovation, School of Chemistry and Chemical Engineering , Henan Normal University , Xinxiang 453007 , China.

Rh(III)-catalyzed cascade C-H activation of benzoylacetonitriles and annulation with sulfoxonium ylides was realized, leading to selective synthesis of naphthols, 2,3-dihydronaphtho[1,8- bc]pyrans, and naphtho[1,8- bc]pyrans. This step-economic reaction proceeded efficiently under mild and redox-neutral conditions via multiple C-H activations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.orglett.8b00420DOI Listing
April 2018

Rh(III)-Catalyzed Diastereodivergent Spiroannulation of Cyclic Imines with Activated Alkenes.

Org Lett 2017 10 27;19(19):5402-5405. Epub 2017 Sep 27.

Henan Key Laboratory of Organic Functional Molecules and Drug Innovation, School of Chemistry and Chemical Engineering, Henan Normal University , Xinxiang 453007, China.

Rh(III)-catalyzed [3 + 2] annulation of cyclic N-sulfonyl or N-acyl ketimines with activated alkenes has been realized, leading to the synthesis of spirocycles with three continuous stereogenic centers. This atom-economic reaction proceeded efficiently under mild and redox-neutral conditions via a C-H activation pathway, and the coupling is diastereodivergent, with the diastereoselectivity being controlled by silver additives.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.orglett.7b02678DOI Listing
October 2017

Rhodium(iii)-catalyzed regio- and stereoselective benzylic α-fluoroalkenylation with gem-difluorostyrenes.

Chem Commun (Camb) 2017 Sep;53(74):10326-10329

Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.

Rhodium(iii)-catalyzed mild benzylic α-fluoroalkenylation of 8-methylquinolines with gem-difluorostyrenes has been developed. This reaction occurred via C-H activation and C-F cleavage and is applicable to a wide range of substrates, leading to the synthesis of Z-alkenyl fluorides under mild and redox-neutral conditions with high regio- and stereoselectivity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c7cc06048cDOI Listing
September 2017

Rhodium(III)-Catalyzed C-H Activation of Nitrones and Annulative Coupling with Nitroalkenes.

J Org Chem 2017 09 30;82(18):9877-9884. Epub 2017 Aug 30.

Henan Key Laboratory of Organic Functional Molecule and Drug Innovation, School of Chemistry and Chemical Engineering, Henan Normal University , Xinxiang 453007, China.

Rh(III)-catalyzed synthesis of nitro-functionalized indenes has been realized via C-H activation of arylnitrones and annulation with nitroolefins. The reaction proceeded in moderate to high yields with good functional group tolerance under ambient atmosphere.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.joc.7b01574DOI Listing
September 2017

Cp*Rh(III)-Catalyzed Mild Addition of C(sp)-H Bonds to α,β-Unsaturated Aldehydes and Ketones.

Org Lett 2017 04 4;19(8):2086-2089. Epub 2017 Apr 4.

Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Henan Normal University , Xinxiang 453007, China.

A Rh(III)-catalyzed addition of benzylic C(sp)-H bond to α,β-unsaturated ketones/aldehydes has been realized, leading to efficient synthesis of γ-aryl ketones/aldehydes. This atom-economic reaction proceeded under mild and redox-neutral conditions with a broad substrate scope. Besides benzylic C-H, allylic C-H bonds are also applicable when assisted by O-methyl ketoxime directing groups.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.orglett.7b00690DOI Listing
April 2017

Ru(II)-catalyzed amidation reactions of 8-methylquinolines with azides via C(sp(3))-H activation.

Chem Commun (Camb) 2015 Nov;51(91):16334-7

State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, P. R. China. and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300071, P. R. China.

Ru(II)-catalyzed amidation reactions of 8-methylquinolines with azides have been developed. They are the first examples of [(p-cymene)RuCl2]2-catalyzed C(sp(3))-H bond intermolecular amidation reactions which give quinolin-8-ylmethanamines under mild reaction conditions in good yields.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c5cc06230fDOI Listing
November 2015

Rhodium(III)-catalyzed alkenylation reactions of 8-methylquinolines with alkynes by C(sp3)-H activation.

Angew Chem Int Ed Engl 2014 Apr 12;53(16):4191-5. Epub 2014 Mar 12.

State Key Laboratory of Elemento-Organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin 300071 (China).

The alkenylation reactions of 8-methylquinolines with alkynes, catalyzed by [{Cp*RhCl2}2], proceeds efficiently to give 8-allylquinolines in good yields by C(sp(3))-H bond activation. These reactions are highly regio- and stereoselective. A catalytically competent five-membered rhodacycle has been structurally characterized, thus revealing a key intermediate in the catalytic cycle.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/anie.201310711DOI Listing
April 2014

Rhodium-catalyzed cascade oxidative annulation leading to substituted naphtho[1,8-bc]pyrans by sequential cleavage of C(sp2)-H/C(sp3)-H and C(sp2)-H/O-H bonds.

J Am Chem Soc 2012 Oct 25;134(39):16163-6. Epub 2012 Sep 25.

State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.

The cascade oxidative annulation reactions of benzoylacetonitrile with internal alkynes proceed efficiently in the presence of a rhodium catalyst and a copper oxidant to give substituted naphtho[1,8-bc]pyrans by sequential cleavage of C(sp(2))-H/C(sp(3))-H and C(sp(2))-H/O-H bonds. These cascade reactions are highly regioselective with unsymmetrical alkynes. Experiments reveal that the first-step reaction proceeds by sequential cleavage of C(sp(2))-H/C(sp(3))-H bonds and annulation with alkynes, leading to 1-naphthols as the intermediate products. Subsequently, 1-naphthols react with alkynes by cleavage of C(sp(2))-H/O-H bonds, affording the 1:2 coupling products. Moreover, some of the naphtho[1,8-bc]pyran products exhibit intense fluorescence in the solid state.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/ja3075242DOI Listing
October 2012
-->