AN OPTICAL YIELD THAT INCREASES WITH TEMPERATURE IN A PHOTOCHEMICALLY INDUCED ENANTIOMERIC ISOMERIZATION
AN OPTICAL YIELD THAT INCREASES WITH TEMPERATURE IN A PHOTOCHEMICALLY INDUCED ENANTIOMERIC ISOMERIZATION
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DOI：
10.1038/341225a0
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发表时间：
1989-09-21
期刊：
影响因子：
64.8
通讯作者：
TAI, A
中科院分区：
文献类型：
--
作者：
INOUE, Y;YOKOYAMA, T;TAI, A
手性转移和手性分子倍增是天然和合成化合物的化学和生化转化过程中的关键过程。由于熵的原因，酶和催化过程中的结构固定化以及低温的使用通常应该提高手性反应中的光学产率(对一个对映体的偏好)。然而，在化学和生化过程中对光学产率的温度依赖性的研究一直是零星的1-10。在这里，我们系统地研究了一个简单的烯烃的光敏化对映异构化反应的温度依赖性。我们发现，在所用光敏剂的临界温度以上，光学产量随着温度的升高而增加，这显然与普遍接受的温度越低有利于光学产量越高的观点相矛盾。因此，使用单一的手性源可以高效地生产这两种对映体。这意味着，自然系统中手性的转移和倍增，这是益生菌有机分子发展的一个重要方面，可能比迄今所认为的要简单得多。
TRANSFER of chirality and multiplication of chiral molecules are key processes in the chemical and biochemical transformations of natural and synthetic compounds. For entropic reasons, structural immobilization in enzymatic and catalytic processes and the use of low temperatures should generally enhance the optical yield (preference for one enantiomer) in chiral reactions. Studies of the temperature dependence of optical yield in chemical and biochemical processes have, however, been sporadic1–10. Here we report a systematic study of the temperature dependence of the photosensitized enantiodifferentiating isomerization of a simple alkene. We find that above a critical temperature, characteristic of the photosensitizer used, the optical yield increases with increasing temperature, apparently conflicting with the widely accepted view that lower temperatures favour a higher optical yield. Thus both enantiomers may be produced with high efficiency using a single chiral source. This implies that transfer and multiplication of chirality in natural systems, an important aspect of the development of prebiotic organic molecules, may be effected rather more simply than has hitherto been supposed.