Employing triflic anhydride/2-fluoropyridine as an activation system, the coupling reactions of secondary N-aryl amides with terminal alkynes yielded substituted quinolines in moderate to excellent yields. The reactio...Employing triflic anhydride/2-fluoropyridine as an activation system, the coupling reactions of secondary N-aryl amides with terminal alkynes yielded substituted quinolines in moderate to excellent yields. The reaction tolerated both electron-donating and electron-withdrawing groups at the benzamide moiety. Electron-rich aryl acetylenes served as excellent coupling partners, and aliphatic terminal alkynes such as cyclopropyl and conjugate vinyl acetylenes could also be used as reaction partners. By means of 2 D NMR techniques(heteronuclear multiple bond correlation(HMBC), heteronuclear single quantum correlation(HSQC)),nitrilium ions were probed as reactive intermediates which are in contrast with that suggested by Movassaghi on the basis of in situ IR monitoring experiments. On the basis of these results, a plausible mechanism for the formation of quinolines was suggested.展开更多
采用量子化学密度泛函B3LYP方法在6-31G**水平上研究了氮杂炔正离子[R C N CH(R1R2)]+与二环[2,2,1]2庚烯的反应机理.优化得到各驻点的几何构型,通过振动分析和内禀反应坐标对过渡态进行了确认,解析了反应路径;并在同一水平上研究了当R...采用量子化学密度泛函B3LYP方法在6-31G**水平上研究了氮杂炔正离子[R C N CH(R1R2)]+与二环[2,2,1]2庚烯的反应机理.优化得到各驻点的几何构型,通过振动分析和内禀反应坐标对过渡态进行了确认,解析了反应路径;并在同一水平上研究了当R,R1和R2分别为不同烷烃取代基的同分异构体时,得到不同产物的反应情况,找出这类反应随取代基不同的变化规律.展开更多
A catalytic two-component three-centered(2C3C)Ugi-type reaction was developed for the synthesis of L-1-deoxynojirimycin(DNJ)isomers using a chiron approach.This new and quite mild catalytic system,comprised of phenylp...A catalytic two-component three-centered(2C3C)Ugi-type reaction was developed for the synthesis of L-1-deoxynojirimycin(DNJ)isomers using a chiron approach.This new and quite mild catalytic system,comprised of phenylphosphinic acid/Nal,was used to synthesize both the L-allo-DNJ and L-altro-DNJ in high yield.展开更多
基金supported by the National Key R&D Program of China (2017YFA0207302)the National Natural Science Foundation of China (21332007, 21672176)+1 种基金the Natural Science Foundation of Fujian Province, China (2017J01021)the Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education, China
文摘Employing triflic anhydride/2-fluoropyridine as an activation system, the coupling reactions of secondary N-aryl amides with terminal alkynes yielded substituted quinolines in moderate to excellent yields. The reaction tolerated both electron-donating and electron-withdrawing groups at the benzamide moiety. Electron-rich aryl acetylenes served as excellent coupling partners, and aliphatic terminal alkynes such as cyclopropyl and conjugate vinyl acetylenes could also be used as reaction partners. By means of 2 D NMR techniques(heteronuclear multiple bond correlation(HMBC), heteronuclear single quantum correlation(HSQC)),nitrilium ions were probed as reactive intermediates which are in contrast with that suggested by Movassaghi on the basis of in situ IR monitoring experiments. On the basis of these results, a plausible mechanism for the formation of quinolines was suggested.
文摘采用量子化学密度泛函B3LYP方法在6-31G**水平上研究了氮杂炔正离子[R C N CH(R1R2)]+与二环[2,2,1]2庚烯的反应机理.优化得到各驻点的几何构型,通过振动分析和内禀反应坐标对过渡态进行了确认,解析了反应路径;并在同一水平上研究了当R,R1和R2分别为不同烷烃取代基的同分异构体时,得到不同产物的反应情况,找出这类反应随取代基不同的变化规律.
文摘A catalytic two-component three-centered(2C3C)Ugi-type reaction was developed for the synthesis of L-1-deoxynojirimycin(DNJ)isomers using a chiron approach.This new and quite mild catalytic system,comprised of phenylphosphinic acid/Nal,was used to synthesize both the L-allo-DNJ and L-altro-DNJ in high yield.
