The synthesis of novel tetrahydroquinolines (THQ) and dihydroquinolines (DHQ) are reported using three practical, scalable synthetic approaches to access highly lipophilic analogues bearing a 6-iodo substituent, each with a different means of cyclisation. A versatile and stable quinolin-2-one intermediate was identified, which could be reduced to the corresponding THQ with borane reagents, or to the DHQ with diisobutylaluminium hydride via a novel elimination that is more favourable at higher temperatures. Coupling these strongly electron-donating scaffolds to electron-accepting moieties caused the resulting structures to exhibit strong fluorescence.
报道了使用三种实用、可扩展的合成方法合成新型四氢喹啉(THQ)和二氢喹啉(DHQ),以获得带有6-碘取代基的高脂溶性类似物。发现了一种多功能且稳定的喹啉-2-酮中间体,可以用硼烷试剂还原为相应的THQ,或者通过一种更有利于高温的新型消除反应用二异丁基铝氢化物还原为DHQ。将这些强电子给予的支架与电子受体基团偶联,导致所得结构表现出强荧光特性。