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sunxuefei

新虫 (正式写手)

[求助] 有机 汉译英 一段话

1.分别研究了TpRu(PPh3)2(OH)催化水化乙腈和末端炔烃的反应。(1)催化水化乙腈:研究发现在干燥的THF溶液中对乙腈进行催化水化,乙腈并没有发生转化。而在添加适量H2O后,反应生成了预测的产物乙酰胺。这说明,水作用对催化水化反应的影响很大。催化机理表明,PPh3配体的空间位阻较大,添加的乙腈首先取代配合物的PPh3配体生成TpRu(PPh3)(CH3CN)(OH),然后加入适量H2O与配合物的OH配体形成氢键,H2O的羟基氧原子亲核进攻乙腈配体的腈基碳原子,经过烯醇式重排生成TpRu(PPh3)(H2O)(NHCOMe),最后乙腈取代H2O配体经过循环反应生成乙酰胺。在添加PPh3和过量H2O后,都会因为阻碍乙腈的取代而降低转化率。(2)催化水化末端炔烃:实验将TpRu(PPh3)2(OH)和TpRu(PPh3)(CH3CN)(OH)分别催化水化苯乙炔和正己炔,经过对比分析,发现催化水化带有供电子基团的末端炔烃的产率要高于带有吸电子基团的末端炔烃,苯乙炔的苯环与炔烃碳形成P-π共轭,使得碳的电负性变小不易与钌中心结合。此外,PPh3配体的空间效应阻碍了炔烃与TpRu(PPh3)2(OH)的结合,影响催化水化反应的进行。
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chemistry2228

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sunxuefei(金币+60, 翻译EPI+1): 2011-05-15 14:43:43
the catalytic hydration of  acetonitrile and terminal alkynes byTpRu(PPh3)2(OH)have been studied.(1)the catalytic hydration of  acetonitrile: Researches indicated that the acetonitrile conversion did not happen in the anhydrous THF. while adding some water to THF, Acetamide was formed. this indicated that water plays an important role in this reaction.
2楼2011-05-15 09:56:52
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chemistry2228

铜虫 (小有名气)

有一点我不明白,既然是催化水化,那么必然没有水是不行的!开头那两句话我有点不明白?
3楼2011-05-15 09:57:54
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chemistry2228

铜虫 (小有名气)

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Catalytic mechanism shows that the stereo-hindrance effect of PPh3 is remarkable.TpRu(PPh3)(CH3CN)(OH)was produced by ligand exchange reaction of acetonitrile and PPh3.
4楼2011-05-15 10:06:49
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chemistry2228

铜虫 (小有名气)

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then the hydrogen-bond between H2O and OH was formed. after the oxygen atom of water nucleophilic attack the carbon atom of cyano, TpRu(PPh3)(H2O)(NHCOMe) was formed by a phosphoenol rearrangement. finally, Acetamide was produced by Cyclic reaction which nvolved  the exchange of acetonitrile and H2O.
5楼2011-05-15 10:21:45
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