…A reaction that uses an ylide of a phosphorus compound (phosphorane or phosphonium) to convert the carbonyl (C=O) of an aldehyde or ketone to a methylene (C=CHR, where R is various substituents). It is called the Wittig reaction or Wittig reaction after its discoverer, Georg Wittig (1897-1987) of West Germany. Until then, there had been no reaction that could convert the carbonyl group of a ketone or aldehyde to C=CHR in one step, but the Wittig reaction made it possible, and Wittig was awarded the Nobel Prize in Chemistry in 1979. … From [Chemistry]…Metal hydrides, such as lithium aluminum hydride, became important reagents in organic synthesis as more powerful reducing agents. Herbert Charles Brown (1912- ) systematized the hydroboration reaction, which adds borane to unsaturated bonds to convert functional groups, while Georg Wittig (1897-1987) developed the carbon chain extension method (Wittig reaction) using phosphorus reagents. In the Wittig reaction, the reaction intermediate ylide plays an important role, and in the 20th century, organic chemistry made remarkable progress in the study of reaction intermediates and unstable molecular species, including ylides. … *Some of the terminology that mentions "Wittig, G." is listed below. Source | Heibonsha World Encyclopedia 2nd Edition | Information |
…リン化合物(ホスホランまたはホスホニウム)のイリドを用いて,アルデヒドまたはケトンのカルボニル(C=O)をメチレン(C=CHR,Rは種々の置換基)に変換する反応。発見者である西ドイツのウィティヒGeorg Wittig(1897‐1987)にちなんでウィティヒ反応またはビッティヒ反応と呼ばれる。それまでケトンやアルデヒドのカルボニル基をC=CHRに1段階で変える反応はなかったが,ウィティヒ反応によってそれが可能となり,ウィティヒは1979年ノーベル化学賞を受賞した。… 【化学】より…水素化リチウムアルミニウムに代表される金属水素化物は,より強力な還元剤として有機合成の重要な試薬となった。ブラウンHerbert Charles Brown(1912‐ )はボランを不飽和結合に付加させて官能基変換を行うヒドロホウ素化反応を体系化する一方,ウィティヒGeorg Wittig(1897‐1987)はリン試薬による炭素鎖延長法(ウィティヒ反応)を開発した。ウィティヒ反応では反応中間体イリドが重要な役割を果たすが,20世紀に入って有機化学はとくにイリドを含めた反応中間体ないし不安定分子種の研究に著しい進歩をみた。… ※「Wittig,G.」について言及している用語解説の一部を掲載しています。 出典|株式会社平凡社世界大百科事典 第2版について | 情報 |
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