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1.
J Org Chem ; 87(24): 16887-16894, 2022 Dec 16.
Article in English | MEDLINE | ID: mdl-36454706

ABSTRACT

Diarylselenides are a representative class of molecules in organoselenium compounds. We herein report a Rh-catalyzed direct diarylation of selenium with benzamide derivatives. The use of elemental selenium as the Se source is intriguing in terms of atom economy, cost, stability, and handling. A series of diarylselenides with amide moieties were readily accessible through directed C-H activation. The intermediacy of electrophilic Se(IV) species was indicated by control experiments.

2.
Chemistry ; 27(71): 17952-17959, 2021 Dec 20.
Article in English | MEDLINE | ID: mdl-34708463

ABSTRACT

Isoselenazolone derivatives have attracted significant research interest because of their potent therapeutic activities and indispensable applications in organic synthesis. Efficient construction of functionalized isoselenazolone scaffolds is still challenging, and thus new synthetic approaches with improved operational simplicity have been of particular interest. In this manuscript, we introduce a rhodium-catalyzed direct selenium annulation by using stable and tractable elemental selenium. A series of benzamides as well as acrylamides were successfully coupled with selenium under mild reaction conditions, and the obtained isoselenazolones could be pivotal synthetic precursors for several organoselenium compounds. Based on the designed control experiments and X-ray absorption spectroscopy measurements, we propose an unprecedented selenation mechanism involving a highly electrophilic Se(IV) species as the reactive selenium donor. The reaction mechanism was further verified by a computational study.


Subject(s)
Selenium , Catalysis , Cyclodextrins
3.
Chem Asian J ; 15(16): 2462-2466, 2020 Aug 17.
Article in English | MEDLINE | ID: mdl-32578956

ABSTRACT

A formal [4+2] propargylic annulation of indoles and pyrrole with ethynyl benzoxazinanones was described. This protocol provides a concise synthesis of tetrahydro-5H-indolo[2,3-b]quinolines and tetrahydro-3H-pyrrolo[3,2-b]quinoline, the core structures of alkaloid frameworks, featuring excellent yields, high diastereoselectivity, mild conditions and wide substrate scope.

4.
Org Lett ; 22(4): 1530-1534, 2020 02 21.
Article in English | MEDLINE | ID: mdl-32009411

ABSTRACT

CuCl/(R,R)-Ph-BPE-catalyzed asymmetric hydroallylation of 1,2-dihydroquinolines, prepared from readily available quinolines, was developed. The optically active tetrahydroquinolines (THQs) bearing an allylic functionality at position 4 were obtained in good yields and excellent enantioselectivity. The introduced allylic groups are amenable to diverse transformations, thus offering chances to rapidly expand the THQ libraries.

5.
Chem Soc Rev ; 49(1): 286-300, 2020 Jan 02.
Article in English | MEDLINE | ID: mdl-31829319

ABSTRACT

We summarize in this review the recent development of chiral phosphoric acid (CPA)-catalyzed asymmetric dearomatization reactions. A wide array of electron-rich arenes (indoles, phenols, naphthols, benzothiophenes, benzofurans, etc.) and electron-poor arenes (pyridines, quinolines, isoquinolines, etc.) has been proved reactive towards various reaction partners in the presence of a CPA catalyst, enabling asymmetric dearomatization reactions that lead to structurally-diverse polycyclic molecules. The reactions are grouped according to the roles of the arenes in the reactions (as nucleophiles or electrophiles) and the types of reaction partners. This review closes with a personal perspective on the dynamic research area of asymmetric dearomatization reactions by CPAs.

6.
Org Lett ; 21(13): 5357-5362, 2019 07 05.
Article in English | MEDLINE | ID: mdl-31247783

ABSTRACT

A 1,2-reductive dearomatization of quinolines and copper(II) acetate monohydrate/( R, R)-Ph-BPE/P( p-tolyl)3-catalyzed enantioselective hydroamination sequence was developed, affording diverse 4-amino-1,2,3,4-tetrahydroquinolines with high levels of enantioselectivity in either a stepwise or one-pot fashion. Pleasingly, internal cis-cyclic alkenes, which are challenging substrates in copper hydride-catalyzed enantioselective hydroamination reactions, were transformed efficiently under mild conditions.

7.
Angew Chem Int Ed Engl ; 57(46): 15204-15208, 2018 11 12.
Article in English | MEDLINE | ID: mdl-30251383

ABSTRACT

A copper(II) acetate/(R)-DTBM-SEGPHOS-catalyzed ring opening of benzofurans and enantioselective hydroamination cascade with dimethoxymethylsilane (DMMS) and hydroxylamine esters is described. Starting from readily available substituted benzofurans, a series of chiral N,N-dibenzylaminophenols, which are of high interest in pharmaceutical chemistry, were obtained with excellent enantioselectivities (up to 66 % yield, 94 % ee).

8.
Zhonghua Liu Xing Bing Xue Za Zhi ; 34(6): 594-7, 2013 Jun.
Article in Chinese | MEDLINE | ID: mdl-24125611

ABSTRACT

OBJECTIVE: To analyze and evaluate the application of China Infectious Diseases Automated-alert and Response System(CIDARS)in Zhejiang province. METHODS: Data through the monitoring program in 2012 was analyzed descriptively and compared with the incidence data in the same period as well information related to public health emergency events. RESULTS: A total of 14 292 signals were generated on 28 kinds of infectious diseases in the system, in Zhejiang province. 100% of the signals had been responded and the median time to response was 0.81 hours. 123 signals (0.86%)were preliminarily verified as suspected outbreaks and 33 outbreaks were finally confirmed by further field investigation, with a positive ratio of 0.23% . Information related to regional distribution showed significant differences which reflecting a positive correlation between the numbers of diseases and the time of early-warning(r = 0. 97, P < 0.01). Distribution of information related to different types of diseases was also significantly different, showing a positive correlation between the prevalent strength of the disease and the amount of information in a specific area(r = 0.80, P < 0.01). CONCLUSION: CIDARS had a good performance which could be used to assist the local public health institutions on early detection of possible outbreaks at the early stage. However, the effectiveness was different for different regions and diseases.


Subject(s)
Communicable Disease Control/methods , Disease Outbreaks/prevention & control , Population Surveillance/methods , China/epidemiology , Communicable Diseases/epidemiology , Humans , Incidence , Public Health
9.
Zhonghua Liu Xing Bing Xue Za Zhi ; 32(5): 442-5, 2011 May.
Article in Chinese | MEDLINE | ID: mdl-21569722

ABSTRACT

OBJECTIVE: To evaluate the performance of China Infectious Disease Automated-alert and Response System (CIDARS). METHODS: A retrospective analysis was conducted on data related to the warning signals, the outcome of signal verification, the field investigation of CIDARS, and the emergent events reported through Public Health Emergency Events Surveillance System from July 1, 2008 to June 30, 2010 in Zhejiang province. The performance of CIDARS was qualitatively evaluated by indicators on its sensitivity and rate of false alarm. RESULTS: In total, 26 446 signals were generated by the system which involving 17 diseases, with an average of 2.83 signals per country per week. Among all the signals, 99.95% of them were responded. 0.90% of the signals were judged as suspected events via the preliminary verification, and 30 outbreaks were finally confirmed by field investigation. The sensitivity of the system was 69.77% with the false alarm rate as 1.39%. CONCLUSION: The system seemed to have worked on the outbreak early warning of infectious diseases and could directly reflect the anomaly event emerged from the infectious disease reporting system. However, more efforts should be paid to the following areas as how to decrease the false positive signals, select suitable thresholds and increase the quality of data in order to enhance the accuracy of the system.


Subject(s)
Disease Notification , Disease Outbreaks , Population Surveillance , China/epidemiology , Communicable Diseases/epidemiology , Disease Outbreaks/prevention & control , Humans
10.
Zhongguo Yi Miao He Mian Yi ; 15(1): 65-7, 2009 Feb.
Article in Chinese | MEDLINE | ID: mdl-20077680

ABSTRACT

OBJECTIVE: To know the status of Immunization program in Zhejiang Province. METHODS: The investigation on immunization program in zhejiang province was conducted, and the SWOT analysis was corducted to make a comprehensive evaluation. RESULTS: 11 cities, 22 counties and 44 towns were investigated in this study, and the current immunization program in Zhejiang province were explored by SWOT analysis. CONCLUSION: The SWOT Matrix, includes SO (strength-opportunity), ST (strength-threat), WO (weakness-opportunity) and WT (weakness-threat) can apply to make optimal strategy for the development of expanded program on immunization.


Subject(s)
Immunization Programs , Program Evaluation , China , Humans
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