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.
本发明涉及五氟磺酰(SF5)取代的吡咯、噻吩、3-吡咯烷和2,5-二氢噻吩,以及它们的合成方法。
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.
conditions for the synthesis of pentafluorosulfanylpyrazoles is reported. A range of alkyl- and aryl-substituted SF5-alkynes were used in combination with different diazoacetates for this transformation. The corresponding substituted SF5-pyrazoles were obtained in up to 90% yield (average of 74% for 21 examples) as a mixture of isomers (up to 73:27 ratio). Synthetic transformations starting from an SF5-containing