Reversible diastereoselective photocyclization of a diarylethene in a single-crystalline phase
Reversible diastereoselective photocyclization of a diarylethene in a single-crystalline phase
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DOI：
10.1021/ja001350o
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发表时间：
2000-10-11
影响因子：
15
通讯作者：
Irie, M
中科院分区：
文献类型：
--
作者：
Kodani, T;Matsuda, K;Irie, M
合成了具有光学活性的(S)-和(R)-1-（2-甲基-5-苯基-3-噻吩基）-2-[2-（3-甲基-1-戊烯-1-基）-5-苯基-3-噻吩基]-3,3,3,4,5,5-六氟环戊烷(（S)-1a和(R)-1a）。x射线晶体学测量表明，(S)-1a和(R)-1a单晶采用正交手性空间群P2(1)2(1)2(1) 2(1)，开环异构体在晶体中仅以可能的两种异位异构体的一种构象排列。在366 nm光照射下，(S)-1a和(R)-1a在溶液和单晶状态下都发生了可逆的光环化反应，在晶体相中几乎只产生一个闭环非对映体，而在溶液中没有观察到非对映体选择。x射线晶体学分析确定(S)-1a产生的优势非对映体为（S，R，R）-1b。
Optically active photochromic (S)- and (R)-1-(2-methyl-5-phenyl-3-thienyl)-2-[2-(3-methyl-1-penten-1-yl)-5-phenyl-3-thienyl]-3,3,3,4,5,5-hexafluorocyclopentanes ((S)-1a and (R)-1a) were synthesized. X-ray crystallographic measurement showed that (S)-1a and (R)-1a single crystals adopted orthorhombic chiral space group P2(1)2(1)2(1) and the open-ring isomers were packed in the crystals in only one conformer of the possible two atropisomers. Upon irradiation with 366 nm light (S)-1a and (R)-1a underwent reversible photocyclization reactions both in solution and in the single-crystalline state, and in the crystalline phase almost only one closed-ring diastereomer was produced, while the diastereoselection was not observed in solution. The dominant diastereomer produced from (S)-1a was determined to be (S,R,R)-1b by X-ray crystallographic analysis.