STERIC ACCELERATION THROUGH REGULATION OF ROTATIONAL CONFORMATION - THE SMILES REARRANGEMENT
STERIC ACCELERATION THROUGH REGULATION OF ROTATIONAL CONFORMATION - THE SMILES REARRANGEMENT
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DOI：
10.1021/ja01601a055
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发表时间：
1956-01-01
影响因子：
15
通讯作者：
OKAMOTO, T
中科院分区：
文献类型：
--
作者：
BUNNETT, JF;OKAMOTO, T
在2-羟基-2 ′-硝基二苯砜的6位引入甲基氯或溴取代基，使重排反应速率提高约50万倍。由于释放电子和吸引电子的6-取代基都引起类似的速率急剧增加，因此加速的起源是空间的而不是电子的。1937年McClement和Smiles 4报道了6-位甲基对2-羟基-2 '-硝基二苯砜Smiles重排反应的促进作用。加速的原因，他们说，是电子从甲基释放到砜桥，从而减少
The rate of rearrangement of a 2-hydroxy-2'-nitrodiphenyl sulfone to a 2-(o-nitrophenoxy)-benzenesulfinic acid is in-creased about 500,000-fold by the introduction of a methyl chloro or bromo substituent in the 6-position. Since both electron-releasing and electron-attracting 6-substituents cause similar tremendousincreases in rate, the origin of the accelera-tion is steric and not electronic. The mechanism of the acceleration is discussed.In 1937, McClement and Smiles4 reported that the Smiles rearrangement of 2-hydroxy-2'-nitro-diphenyl sulfones to 2-(o-nitrophenoxy)-benzenesulfinic acids is accelerated by methyl groups in the 6-position. The cause of the acceleration, they said, was electron-release from the methyl group to the sulfone bridge which thereby was rendered less