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  1. Article: Rhodium-Catalyzed Three-Component Reaction of Alkynes, Arylzinc Chlorides, and Iodomethanes Producing Trisubstituted/Tetrasubstituted Alkenes with/without 1,4-Migration

    Meng, He / Bai, Shiming / Qiao, Yu / He, Ting / Li, Weiyi / Ming, Jialin

    Organic letters. 2022 July 20, v. 24, no. 29

    2022  

    Abstract: A three-component reaction of alkynes, arylzinc chlorides, and iodomethanes was found to proceed in the presence of a rhodium catalyst to give high yields of trisubstituted/tetrasubstituted alkenes. The usual arylzinc chlorides only gave trisubstituted ... ...

    Abstract A three-component reaction of alkynes, arylzinc chlorides, and iodomethanes was found to proceed in the presence of a rhodium catalyst to give high yields of trisubstituted/tetrasubstituted alkenes. The usual arylzinc chlorides only gave trisubstituted alkenes, generated through a migratory carbozincation–cross-coupling sequence, where 1,4-Rh migration from an alkenyl carbon to an aryl carbon occurred. In contrast, 5-membered heteroarylzinc chlorides only gave the tetrasubstituted alkenes via a carborhodation–cross-coupling pathway without 1,4-migration.
    Keywords alkenes ; alkynes ; carbon ; catalysts ; migratory behavior ; rhodium
    Language English
    Dates of publication 2022-0720
    Size p. 5480-5485.
    Publishing place American Chemical Society
    Document type Article
    ISSN 1523-7052
    DOI 10.1021/acs.orglett.2c02299
    Database NAL-Catalogue (AGRICOLA)

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  2. Article: Rhodium-Catalyzed Desymmetric Arylation of γ,γ-Disubsituted Cyclohexadienones: Asymmetric Synthesis of Chiral All-Carbon Quaternary Centers

    Qiao, Yu / Bai, Shiming / Wu, Xiao-Feng / Yang, Ying / Meng, He / Ming, Jialin

    Organic letters. 2022 Feb. 10, v. 24, no. 7

    2022  

    Abstract: The desymmetric arylation of prochiral cyclohexadienones with ArZnCl in the presence of an (R)-segphos–rhodium catalyst gave high yields of the corresponding cyclohexenones, which contain a chiral arylated carbon center at the β-position and a chiral all- ...

    Abstract The desymmetric arylation of prochiral cyclohexadienones with ArZnCl in the presence of an (R)-segphos–rhodium catalyst gave high yields of the corresponding cyclohexenones, which contain a chiral arylated carbon center at the β-position and a chiral all-carbon quaternary center at the γ-position, with high diastereo- and enantioselectivities. This catalytic system was also applied to the arylation of spirocarbocyclic cyclohexadienones and afforded the corresponding cyclohexenones bearing a chiral spiro quaternary carbon with high dr and ee.
    Keywords arylation ; carbon ; catalysts ; stereoselective synthesis
    Language English
    Dates of publication 2022-0210
    Size p. 1556-1560.
    Publishing place American Chemical Society
    Document type Article
    ISSN 1523-7052
    DOI 10.1021/acs.orglett.2c00225
    Database NAL-Catalogue (AGRICOLA)

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  3. Article ; Online: Rhodium-Catalyzed Three-Component Reaction of Alkynes, Arylzinc Chlorides, and Iodomethanes Producing Trisubstituted/Tetrasubstituted Alkenes with/without 1,4-Migration.

    Meng, He / Bai, Shiming / Qiao, Yu / He, Ting / Li, Weiyi / Ming, Jialin

    Organic letters

    2022  Volume 24, Issue 29, Page(s) 5480–5485

    Abstract: A three-component reaction of alkynes, arylzinc chlorides, and iodomethanes was found to proceed in the presence of a rhodium catalyst to give high yields of trisubstituted/tetrasubstituted alkenes. The usual arylzinc chlorides only gave trisubstituted ... ...

    Abstract A three-component reaction of alkynes, arylzinc chlorides, and iodomethanes was found to proceed in the presence of a rhodium catalyst to give high yields of trisubstituted/tetrasubstituted alkenes. The usual arylzinc chlorides only gave trisubstituted alkenes, generated through a migratory carbozincation-cross-coupling sequence, where 1,4-Rh migration from an alkenyl carbon to an aryl carbon occurred. In contrast, 5-membered heteroarylzinc chlorides only gave the tetrasubstituted alkenes via a carborhodation-cross-coupling pathway without 1,4-migration.
    Language English
    Publishing date 2022-07-20
    Publishing country United States
    Document type Journal Article
    ISSN 1523-7052
    ISSN (online) 1523-7052
    DOI 10.1021/acs.orglett.2c02299
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    Inter-library loan at ZB MED

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  4. Article ; Online: Rhodium-Catalyzed Desymmetric Arylation of

    Qiao, Yu / Bai, Shiming / Wu, Xiao-Feng / Yang, Ying / Meng, He / Ming, Jialin

    Organic letters

    2022  Volume 24, Issue 7, Page(s) 1556–1560

    Abstract: The desymmetric arylation of prochiral cyclohexadienones with ArZnCl in the presence of an ( ...

    Abstract The desymmetric arylation of prochiral cyclohexadienones with ArZnCl in the presence of an (
    Language English
    Publishing date 2022-02-10
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1523-7052
    ISSN (online) 1523-7052
    DOI 10.1021/acs.orglett.2c00225
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    Kategorien

    Order via subito

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    Inter-library loan at ZB MED

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  5. Article ; Online: Synthetic galactomannans with potent anti-HIV activity.

    Budragchaa, Davaanyam / Bai, Shiming / Kanamoto, Taisei / Nakashima, Hideki / Han, Shuqin / Yoshida, Takashi

    Carbohydrate polymers

    2015  Volume 130, Page(s) 233–242

    Abstract: Ring-opening polymerization of a new 1,6-anhydro disaccharide monomer, 1, 6-anhydro-2, 3-di-O-benzyl-4-O-(2', 3', 4', 6'-tetra-O-benzyl-α-d-galactopyranosyl)-α-d-mannopyranose, was carried out using PF5 as a catalyst under high vacuum at -60°C to give ... ...

    Abstract Ring-opening polymerization of a new 1,6-anhydro disaccharide monomer, 1, 6-anhydro-2, 3-di-O-benzyl-4-O-(2', 3', 4', 6'-tetra-O-benzyl-α-d-galactopyranosyl)-α-d-mannopyranose, was carried out using PF5 as a catalyst under high vacuum at -60°C to give galactose branched mannopyranan (synthetic galactomannan), 4-O-α-d-galactopyranosyl-(1→6)-α-d-mannopyranan, after debenzylation with Na in liquid NH3. The ring-opening copolymerization with 1, 6-anhydro-tri-O-benzyl-α-d-mannopyranose in various feeds was also performed to give synthetic galactomannans with various proportions of galactose branches. After sulfation, sulfated synthetic galactomannans were found to have anti-HIV activity and cytotoxicity as high and low as those of standard curdlan and dextran sulfates, respectively, which are potent anti-HIV sulfated polysaccharides with low cytotoxicity. The anti-HIV mechanism of sulfated synthetic galactomannans used by poly-l-lysine as a model peptide of the HIV surface protein was estimated by using SPR, DSL, and zeta potential measurements, revealing the electrostatic interaction between negatively charged sulfate groups and positively charged amino groups.
    MeSH term(s) Anti-HIV Agents/chemical synthesis ; Anti-HIV Agents/pharmacology ; Cell Proliferation/drug effects ; Cells, Cultured ; HIV/drug effects ; HIV Infections/drug therapy ; HIV Infections/virology ; Humans ; Mannans/chemical synthesis ; Mannans/pharmacology ; Polylysine/chemistry
    Chemical Substances Anti-HIV Agents ; Mannans ; galactomannan (11078-30-1) ; Polylysine (25104-18-1)
    Language English
    Publishing date 2015-10-05
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1501516-6
    ISSN 1879-1344 ; 0144-8617
    ISSN (online) 1879-1344
    ISSN 0144-8617
    DOI 10.1016/j.carbpol.2015.04.047
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Correlation between miR-23a and onset of hepatocellular carcinoma.

    Bao, Lidao / Zhao, Jianfen / Dai, Xiaoxia / Wang, Yi / Ma, Ruilian / Su, Yila / Cui, Hongwei / Niu, Jianxiang / Bai, Shiming / Xiao, Zhiying / Yuan, Hongwei / Yang, Zhou / Li, Changqing / Cheng, Rui / Ren, Xianhua

    Clinics and research in hepatology and gastroenterology

    2014  Volume 38, Issue 3, Page(s) 318–330

    Abstract: Background and aims: To clarify the role of miR-23a in the onset and development of hepatocarcinoma on the cellular, genetic and molecular levels.: Patients and methods: Seventy-eight patients were included after hepatectomy. Relationships between ... ...

    Abstract Background and aims: To clarify the role of miR-23a in the onset and development of hepatocarcinoma on the cellular, genetic and molecular levels.
    Patients and methods: Seventy-eight patients were included after hepatectomy. Relationships between the clinical pathological factors of tumor and paracancerous tissues were analyzed. Risk factors of overall and recurrence-free survival rates were subject to multi-variable analysis. Tissues were sequenced by digital miRNA expression profiling, and new miRNA was subject to target gene prediction.
    Results: miR-23a expression was correlated with the stage of the TNM Classification of Malignant Tumours most significantly, followed by tumor size (P=0.041 and 0.047). High miR-23a, vascular invasion, tumor size≥7cm, tumor capsule and late pathological stage were the risk factors of overall survival rate, and those of recurrence-free survival rate also included alpha-fetoprotein level≥200μg/L and multiple tumors. Compared with normal hepatic cell line L-02, the miR-23a expression levels in tumor cell lines SMMC-7721 and HepG2 were up-regulated and down-regulated respectively. Transfecting miR-23a inhibitor suppressed cell growth. Apoptotic rates of the control and those transfected with inhibitor-NC and miR-23a inhibitor for 48h were similar.
    Conclusion: High miR-23a expression is the independent prognostic factor of overall and recurrence-free survival rates, and miR-23a may be involved in the onset of hepatocarcinoma as an oncogene.
    MeSH term(s) Aged ; Aged, 80 and over ; Apoptosis ; Carcinoma, Hepatocellular/genetics ; Carcinoma, Hepatocellular/pathology ; Cell Line ; Down-Regulation ; Female ; High-Throughput Nucleotide Sequencing ; Humans ; Liver/pathology ; Liver Neoplasms/genetics ; Liver Neoplasms/pathology ; Male ; MicroRNAs/genetics ; MicroRNAs/metabolism ; Middle Aged ; Neoplasm Invasiveness ; Precancerous Conditions/genetics ; Precancerous Conditions/pathology ; Real-Time Polymerase Chain Reaction ; Risk Factors ; Up-Regulation ; alpha-Fetoproteins/analysis
    Chemical Substances MIRN23a microRNA, human ; MicroRNAs ; alpha-Fetoproteins
    Language English
    Publishing date 2014-01-10
    Publishing country France
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2594333-9
    ISSN 2210-741X ; 2210-7401
    ISSN (online) 2210-741X
    ISSN 2210-7401
    DOI 10.1016/j.clinre.2013.12.002
    Database MEDical Literature Analysis and Retrieval System OnLINE

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