DEVELOPING ARTIFICIAL HYDROLYTIC METALLOENZYMES BY A UNIFIED MECHANISTIC APPROACH
DEVELOPING ARTIFICIAL HYDROLYTIC METALLOENZYMES BY A UNIFIED MECHANISTIC APPROACH
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DOI：
10.1021/ar00005a004
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发表时间：
1991-05-01
影响因子：
18.3
通讯作者：
CHIN, J
中科院分区：
文献类型：
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作者：
CHIN, J
在构象刚性的2-但-3-烯基环己基自由基环化的研究中，我们已经明确地表明，反应的立体化学结果受到丁基侧链取向的严重影响；平伏丁烯基主要生成1,5 -顺式环化产物，而轴向丁烯基优先生成1,5 -反式环化产物。47这些立体化学结果可以由Beckwith及其同事最初提出的环己烷“椅状”过渡态来令人满意地解释。在相关但构象刚性较低的体系中，具有平伏丁烯侧链和轴向丁烯侧链的过渡态可能相互竞争。小环-
Conclusions In this study of cyclizations of conformationally rigid 2-but-3-enylcyclohexyl radicals, we have conclusively shown that the stereochemical outcome of the reaction is critically influencedby the orientation of the butenyl side chain; an equatorial butenyl group leads predom-inantly to 1, 5-cis cyclization products, whereas an axial butenyl group preferentially gives rise to 1, 5-trans products. 47 These stereochemical consequences can be satisfactorily accounted for by the cyclohexane “chairlike" transition states originally proposed by Beckwith and co-workers for acyclic hex-5-enyl radical cycliza-tions. In related but conformationally less rigid systems, the transition states having an equatorial and an axial butenyl side chain may compete. Minor ring-