Synthesis of Novel Bis(benzoxazole) Derivatives by Tandem Claisen Rearrangement and Their Fluorescence Behavior
作者:Emiko Koyama、Gang Yang、Seiji Tsuzuki、Kazuhisa Hiratani
DOI:10.1002/1099-0690(200206)2002:12<1996::aid-ejoc1996>3.0.co;2-q
日期:2002.6
Novel bis(benzoxazole) derivatives were easily synthesized from isobutenyl bis(amide−ether)s by tandem Claisen rearrangement and subsequent intramolecular cyclization of the amide−phenol intermediates. The yields of the bis(benzoxazole)s depended on whether the reaction was carried out with or without solvent, as well as on the substituents on the aryl group and the carbonyl group. The solvent effect
通过串联克莱森重排和随后酰胺-苯酚中间体的分子内环化,从异丁烯基双(酰胺-醚)很容易合成新的双(苯并恶唑)衍生物。双(苯并恶唑)的产率取决于反应是否在有或没有溶剂的情况下进行,以及芳基和羰基上的取代基。溶剂效应是显着的。观察到随着羰基上取代基的变化,总反应速率常数没有显着差异,但醚上芳基的性质对串联克莱森重排有很大影响。相应的酰胺-苯酚衍生物被确认为该重排的中间体。所得双(苯并恶唑)的荧光量子产率高,但产率低于相应的单苯并恶唑。(© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)