Regioselective Gold-Catalyzed Hydration of CF3- and SF5-alkynes
摘要:
The regioselective gold-catalyzed hydration of CF3- and SF5-alkynes is described. The corresponding trifluoromethylated and pentasulfanylated ketones are obtained in up to 91% yield as single regioisomers showcasing the use of CF3 and SF5 as highly efficient directing groups in this reaction. Notably, this transformation represents the first use of CF3- and SF5-alkynes in gold catalysis.
The gold-catalyzed hydrofluorination reaction of internal alkynes using hydrofluoric acid is reported. Notably, those conditions use one of the most economical sources of HF and are free of additional additives. Both symmetrical and unsymmetrical internal alkynes can be utilized, and the use of alkynes bearing a fluorinated group at the propargylic position as substrates allowed for a regioselective
PREPARATION OF PENTAFLUOROSULFANYL (SF5) HETEROCYCLES: PYRROLES AND THIOPHENES
申请人:Zheng Zhaoyun
公开号:US20110040103A1
公开(公告)日:2011-02-17
The subject invention pertains to pentafluorosulfonyl (SF5) substituted pyrroles, thiophenes, 3-pyrrolines and 2,5-dihydrothiophenes, as well as methods for their synthesis.
Preparation of Pentafluorosulfanyl (SF<sub>5</sub>) Pyrrole Carboxylic Acid Esters
作者:William R. Dolbier、Zhaoyun Zheng
DOI:10.1021/jo9007699
日期:2009.8.7
paper, a facile preparation of SF5-substituted pyrrole carboxylic acid esters in good yield is reported. Utilizing the cycloaddition of an azomethine ylide to pentafluorosulfanylalkynes, a series of dihydropyrroles were prepared and oxidized to the respective 1-tert-butyl-4-(pentafluorosulfanyl)pyrrole-2-carboxylic acid esters in good yield. Further treatment of these pyrroles with catalytic triflic
Use of 1,3-dipolar reactions for the preparation of SF5-substituted five-membered ring heterocycles. Pyrroles and thiophenes
作者:William R. Dolbier、Zhaoyun Zheng
DOI:10.1016/j.jfluchem.2011.03.017
日期:2011.6
4-pentafluorosulfanylthiophenes, the latter of which are to our knowledge the first reported SF5-substituted thiophenes. The 1,3-cycloadditions of these ylides with aryl and alkyl, SF5-alkynes produce dihydro-pyrroles and thiophenes, which without isolation can then be oxidatively aromatized to the respective pentafluorosulfanylpyrroles and thiophenes in good yield.
transition-metal-free and stereoselective approach for the synthesis of Z-vinyl fluorides from alkynes containing unexplored SF5 and SF4 groups has been reported. TBAF ⋅ 3H2O exhibits high compatibility, allowing for easy incorporation of fluoride into SF5 and SF4 alkynes at roomtemperature. Competitive experiments and DFT calculations verify that SF5 alkynes react much faster than SF4 alkynes.
已经报道了一种由含有未探索的SF 5和SF 4基团的炔烃合成Z-乙烯基氟化物的无过渡金属和立体选择性方法。 TBAF·3H 2 O具有高相容性,可以在室温下轻松将氟化物引入SF 5和SF 4炔烃中。竞争性实验和 DFT 计算证实 SF 5炔烃的反应速度比 SF 4炔烃快得多。