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nbm110

金虫 (小有名气)

[求助] (有机化学)求达人闲暇无聊时帮忙翻译一段话~~嫌金币少可追加~~

Cyclization of preformed 2-alkynylanilid(n)es. The cycliza-
tion of N-methanesulfonyl-, N-ethoxycarbonyl-, N-tosyl-2-
alkynylanilides in the presence of Cu(II) salts (Scheme 1, dis-
connection a) produces the corresponding N-protected indoles
(Scheme 2a–c).N-Methanesulfonyl-2-alkynylanilides can also
be converted to indoles in a mixture of H2O and MeOH at room
temperature in the presence of 1-ethylpiperidine (Scheme 2e).Using 2-alkynylanilines as the substrates (Scheme 2d)provides access to free N–H indoles. Cu(OTf)2,Cu(OBz)2 and
Cu(OCOCF3)2·xH2O proved to be efficient catalysts, with thelatter producing the fastest and cleanest reaction. The application
of this cyclization process to 2-alkynylanilines is particularly
interesting in that the final target of many indole syntheses is the
free N–H indole and the cleavage of the N-protecting substituent
after cyclization adds one more step to the synthetic process.
Very likely, the catalytic process starts from the coordination
of the acetylene moiety to copper followed by the intramolecular
nucleophilic attack of the nitrogen nucleophile onto the activated
C–C triple bond to give an indolylcopper intermediate. The indole
product is subsequently formed via substitution of the C–H bond
for the C–Cu bond (Scheme 3).

[ Last edited by nbm110 on 2012-2-7 at 20:13 ]
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小刘渊

金虫 (正式写手)

【答案】应助回帖

nbm110(金币+50, 翻译EPI+1): ★★★★★最佳答案 很不错~~对我来说够用了~ 2012-02-08 11:43:35
我估计你这篇文章是中国人写的吧,看这种风格像是中国人的。如果看我翻译的不错,请给我金币,

翻译如下,仅供参考,如有不足,请多多见谅:

预制2-乙炔基苯胺的环化。在二价铜盐存在的条件下,N-甲磺酰基,N-乙酯基,N-磺酰基-2-乙炔基苯胺的环化可以制备相应的N-保护的哚吲。此外,在水和甲醇的混合溶液中,而且含有1-甲基哌啶的条件下,室温下N-甲磺酰基-2-乙炔基苯胺同样可以转换为哚吲。使用2-乙炔基苯胺作为基材可以制备不含有N-H的哚吲。Cu(OTf)2,Cu(OBz)2,和 Cu(OCOCF3)2•xH2O都是有效的催化剂,而且实验证明使用后者作为催化剂可以得到反应更快,更加清洁的反应体系。使用2-乙炔基苯胺的环化来制备无N-H的哚吲特别适合于以下场合:最终产物是不含N-H的哚吲和合成,此外,还适合于需要在环化后增加去除N-取代保护的反应,而这使用其它物质制备时,往往在环化后需要增加一步工艺。(就是说用2-乙炔基苯胺的环化制备的时候,就能省略这一步)。非常相似的是,催化过程是从乙炔基和铜的反应开始,接着是分子内氮原子对碳碳三键的亲核反应,生成一个哚吲铜的中间体。该中间体随即由C–H取代C–Cu并生成哚吲。
2楼2012-02-08 09:36:42
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