In Situ Evaluation of Kinetic Resolution Catalysts for Nitroaldol by Rationally Designed Fluorescence Probe

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• 作者：Takuya Matsumoto ; Yasuteru Urano ; Yoshinori Takahashi ; Yusuke Mori ; Takuya Terai ; Tetsuo Nagano
• 刊名：Journal of Organic Chemistry
• 出版年：2011
• 出版时间：May 20, 2011
• 年：2011
• 卷：76
• 期：10
• 页码：3616-3625
• 全文大小：1145K
• 年卷期：v.76,no.10(May 20, 2011)
• ISSN：1520-6904

文摘

Development of effective chemical catalysts is a key concern in organic chemistry. Therefore, convenient screening systems for chemical catalysts are required, and although some fluorescence-based HTS systems have been developed, little attempt has been made to apply them to asymmetric catalysts. Therefore, we tried to develop a chiral fluorescence probe which can evaluate the reactivity and enantioselectivity of asymmetric catalysts. We focused on kinetic resolution catalysts as a target of our novel fluorescence probe, employing 尾-elimination following acylation of nitroaldol. Once the hydroxyl group of nitroaldol is acylated, 尾-elimination occurs immediately, affording nitro olefin. Therefore, we designed and synthesized a fluorescence probe with an asymmetric nitroaldol moiety. Its fluorescence intensity decreases dramatically upon 尾-elimination, so the fluorescence decrease is an indicator of the reaction yield. Thus, the enantioselectivity of kinetic resolution catalysts can be assessed simply by measuring the fluorescence intensities of the reaction mixtures of the two enantiomers; it is not necessary to purify the product. This fluorescence probe revealed that benzotetramisole is a superior catalyst for kinetic resolution of nitroaldol. Furthermore, we established an HTS system for asymmetric catalysts, using a fluorescence probe and benzotetramisole. To our knowledge, this is the first fluorescence-based HTS system for asymmetric catalysts.