Intriguing <I>E-</I>/<I>Z-</I>Geometry Selection of Di- and Triaryl Substituted ethenes prepared by the McMurry Reaction

DOI

Bibliographic Information

Other Title
  • マクマリー反応による二及び三アリール置換エテン生成の<I>E</I>, <I>Z</I>選択性

Description

The McMurry crossed coupling reactions of p,p'-disubstituted benzophenones (1) with pivalaldehyde (Pv) gave the corresponding ethenes (2) in fair to excellent yield. The observed geometrical selectivity is varied depending on a kind of p-substituent of the aromatic moiety of 1, when p'-substituent is limited to methyl. According to the known reaction mechanism, the reason why the geometry selection occurred is discussed by a conformational analysis of a possible intermediate, titanium bound pinacolate, and molecular orbital calculations of the starting carbonyl compounds. As a result, the selection is caused by electronic and stereochemical structures of anion radical of 1 and approaching mode of Pv anion radical to them. Distribution of a spin density and unsymmetrical nature of two aromatic moieties of anion radical of 1 provide predetermined pathway to bring about the pinacolate without any rotational conversion under the reaction conditions. Subsequent workup affords 2 with the observed geometry.

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Details 詳細情報について

  • CRID
    1390001205554116352
  • NII Article ID
    130004645830
  • DOI
    10.11494/kisoyuki.2011.0.316.0
  • Text Lang
    ja
  • Data Source
    • JaLC
    • CiNii Articles
  • Abstract License Flag
    Disallowed

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