Anthraquinodimethane Ring-Flip in Sterically Congested Alkenes: Isolation of Isomer and Elucidation of Intermediate through Experimental and Theoretical Approach
Anthraquinodimethane Ring-Flip in Sterically Congested Alkenes: Isolation of Isomer and Elucidation of Intermediate through Experimental and Theoretical Approach
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DOI：
10.1246/bcsj.20210355
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发表时间：
2022-01-01
影响因子：
4
通讯作者：
Suzuki, Takanori
中科院分区：
文献类型：
--
作者：
Ishigaki, Yusuke;Tadokoro, Tomoki;Suzuki, Takanori
从分子反应系统发展的角度来看，刺激诱导的多构象/多构型过度拥挤乙烯的转换是一个有趣的问题，其性质可以通过了解详细的异构化路径来控制。炭疽病-甲烷（AQD）的环翻转通常是一个非常快的过程，因此实验研究较少。本文中，我们研究了具有二苯并和三苯并环庚三烯基的AQD，它们具有足够大的空间位阻，可以延缓AQD的环翻转，从而可以通过实验确定δ G（不相等）值。用人工力诱导反应法对中间体的热异构化进行了研究。基于新制备的AQD的结构不对称性，首次用x射线分离并分析了其中一个通过AQD环翻转发生可逆构象变化的同分异构体。
From the viewpoint of the development of molecular response systems, stimulus-induced switching of multi-conformational/multi-configurational overcrowded ethylenes are interesting, whose properties could be manipulated by understanding the detailed isomerization paths. Anthraquinodi-methane (AQD) ring-flip is usually a very fast process, and thus less studied experimentally. Herein, we studied AQDs with dibenzo- and tribenzocycloheptatrienylidene units, which have large enough steric hindrance to retard the AQD ring-flip to allow determination of the Delta G(not equal) value experimentally. Their thermal isomerization was also scrutinized using the artificial force induced reaction method to elucidate the intermediates. Based on the structural unsymmetry in a newly prepared AQD, one of the isomers that undergoes a reversible conformational change via AQD ring-flip was isolated and analyzed by X-ray for the first time.