Synthesis and Structures of [2. n ]Metacyclophan-1-enes and their Conversion to Highly Strained [2. n ]Metacyclophane-1-ynes
Synthesis and Structures of [2. n ]Metacyclophan-1-enes and their Conversion to Highly Strained [2. n ]Metacyclophane-1-ynes
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[2]的合成和结构。
DOI：
10.1002/ejoc.202000548
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发表时间：
2020
影响因子：
2.8
通讯作者：
Akther T
中科院分区：
文献类型：
--
作者：
Akther T
报道了1，n-双（3-甲酰基-4-甲氧基苯基）烷烃的McMurry环化反应，高产率地合成了顺-[2.n]间环蕃-1-烯（n= 5，6，8）.通过连续的溴化和脱溴化氢反应实现了顺式[2.6]-和[2.8]间环番-1-烯向相应的高应变顺式[2.6]-和[2.8]间环番-1-炔的转化。由于[2.5]间环芳-1-炔的环尺寸较小且结构紧张，因此尝试通过Diels-Alder反应与1，3-二苯基异苯并呋喃进行捕获反应失败。X-射线晶体学分析表明，在syn-[2.6]-和[2.8]metacyclophane-1-ynes中的三键从线性畸变，键角分别为156.7°和161.4°。用密度泛函理论计算了目标化合物不同构象的稳定性。
The syntheses ofsyn‐[2.n]metacyclophan‐1‐enes (n= 5, 6, 8) in good yields using the McMurry cyclization of 1,n‐bis(3‐formyl‐4‐methoxyphenyl)alkanes are reported. Conversion ofsyn‐[2.6]‐ and [2.8]metacyclophan‐1‐enes to the corresponding highly strainedsyn‐type [2.6]‐ and [2.8]metacyclophane‐1‐ynes was achieved by successive bromination and dehydrobromination reactions. An attempted trapping reaction of the putative corresponding [2.5]metacyclophane‐1‐yne by Diels–Alder reaction with 1,3‐diphenylisobenzofuran failed due to its smaller ring size and strained structure. X‐ray crystallographic analyses show that the triple bonds insyn‐[2.6]‐ and [2.8]metacyclophane‐1‐ynes are distorted from linearity with bond angles of 156.7° and 161.4°, respectively. A DFT (Density Functional Theory) computational study was conducted to determine the stabilities of different conformations of the target compounds.