Synthesis, Structure, and Dynamics of Chiral Eight‐Membered Cyclic Molecules with Thienylene and Cyclopropylene Units Alternately Connected
Synthesis, Structure, and Dynamics of Chiral Eight‐Membered Cyclic Molecules with Thienylene and Cyclopropylene Units Alternately Connected
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噻吩基和环丙烯单元交替连接的手性八元环状分子的合成、结构和动力学
DOI：
10.1002/chem.202103962
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Murakami Masahiro
中科院分区：
文献类型：
--
作者：
Miura Tomoya;Ishihara Yumi;Nakamuro Takayuki;Moritani Shunsuke;Nagata Yuuya;Murakami Masahiro
研究了在噻吩环的2,3 -和3,4 -位置上具有三唑基和乙烯基的双功能单体在铑（II）催化下的不对称环寡聚反应。结构上有趣的环二聚体，其中乙烯和环丙烯单元交替连接作为主要成分。中心的八元环是非平面的，呈桶形构象。通过电子圆二色性光谱测量，我们还观察到由桶与桶之间的环翻转引起的外消旋现象，其活化能为108 kJ mol - 1。
A rhodium(II)‐catalyzed asymmetric cyclooligomerization of bifunctional monomers possessing triazolyl and vinyl groups at 2,3‐ and 3,4‐positions on the thiophene ring is studied. Structurally interesting cyclic dimers in which thienylene and cyclopropylene units are alternately connected are obtained as the major components. The eight‐membered rings in the center are non‐planar and adopt a tub‐shaped conformation. We also observe the phenomenon of racemization caused by a tub‐to‐tub ring‐flipping, the activation energy of which is determined as 108 kJ mol−1by electronic circular dichroism spectra measurement.