Diastereoselective [2+2] photocycloaddition of stilbene to chiral fumarate. Direct versus charge-transfer excitation
Diastereoselective [2+2] photocycloaddition of stilbene to chiral fumarate. Direct versus charge-transfer excitation
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DOI：
10.1021/ja0370140
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发表时间：
2004-02-18
影响因子：
15
通讯作者：
Inoue, Y
中科院分区：
文献类型：
--
作者：
Saito, H;Mori, T;Inoue, Y
在（E）-二苯乙烯与富马酸双（（R）-1-甲基丙基）酯的[2 + 2]光环化加成反应中，选择性激发电荷转移（CT）复合物和直接激发底物得到了明显不同的产物比和非对映体过量（de's），以及它们的温度依赖性，清楚地表明激发的CT复合物和传统的激基复合物在结构和反应性上不同。这一结论得到了相关激发物种所表现出的对比荧光行为的支持，特别是在低温下。
The selective excitation of the charge-transfer (CT) complex and the direct excitation of the substrate gave distinctly different product ratios and diastereomeric excesses (de's), as well as their temperature dependencies, in [2 + 2] photocycloaddition of (E)-stilbene to bis((R)-1-methylpropyl) fumarate, clearly demonstrating that the excited CT complex and the conventional exciplex differ in structure and reactivity. This conclusion is supported by the contrasting fluorescence behavior exhibited by the relevant excited species, particularly at low temperatures.