Novel Pd(II)- and Pt(II)-Catalyzed Regio- and Stereoselective trans-Hydroarylation of Alkynes by Simple Arenes

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• 作者：Chengguo Jia ; Wenjun Lu ; Juzo Oyamada ; Tsugio Kitamura ; Kenji Matsuda ; Masahiro Irie ; and Yuzo Fujiwara
• 刊名：Journal of the American Chemical Society
• 出版年：2000
• 出版时间：August 2, 2000
• 年：2000
• 卷：122
• 期：30
• 页码：7252 - 7263
• 全文大小：384K
• 年卷期：v.122,no.30(August 2, 2000)
• ISSN：1520-5126

文摘

Efficient trans-hydroarylation of alkynes by simple arenes has been realized regio- and stereoselectively at room temperature in the presence of Pd(II) or Pt(II) catalysts and a mixed solvent containingtrifluoroacetic acid (TFA). Various arenes undergo trans-hydroarylation selectively across terminal and internalC-C triple bonds-including those conjugated to CHO, COMe, CO₂H, and CO₂Et groups, affording kineticallycontrolled cis-arylalkenes predominantly in most cases, especially, in good yields for electron-rich arenes andactivated alkynes. The formation of arene/alkyne 1/2 or 2/1 adducts as side products is dependent on thearenes' and alkynes' substituents, which can be suppressed in some cases by changing the catalyst, catalystconcentration, and reaction time. The Pt(II) system, PtCl₂/2AgOAc/TFA, shows lower catalytic activity thanPd(OAc)₂/TFA, but higher selectivity, giving higher yields of adducts at the same conversion. On the basis ofseveral isotope experiments and control reactions, a possible mechanism involving electrophilic metalation ofaromatic C-H bonds by in-situ-generated cationic Pd(II) and Pt(II) species leading to intermolecular trans-arylpalladation to alkynes has been discussed.