Visible-Light-Mediated Oxidative Dimerization of Arylalkynes in the Open Air: Stereoselective Synthesis of (<i>Z</i>)-1,4-Enediones
作者:Donglei Wei、Fushun Liang
DOI:10.1021/acs.orglett.6b02926
日期:2016.11.18
An organic photoredox catalytic one-pot protocol is developed for the highly stereoselective synthesis of (Z)-1,4-enediones. The reaction starts directly from alkyne precursors, using 4-(4-cyanophenyl)-2,6-diphenylpyrylium tetrafluoroborate (CN-TPT) as an efficient photosensitizer and dioxygen in the air as a green oxidant. A Csp–Csp oxidative coupling/[4 + 2] cyclization (with dioxygen)/fragmentive
开发了一种有机光氧化还原催化一锅法,用于高度立体选择性地合成(Z)-1,4-二烯酮。该反应直接从炔烃前体开始,使用四氟硼酸4-(4-氰基苯基)-2,6-二苯基吡啶鎓(CN-TPT)作为有效的光敏剂,并在空气中使用双氧作为绿色氧化剂。提出了AC sp –C sp氧化偶合/ [4 + 2]环化(含双氧)/碎片异构化的级联机理。(Z)-1,4-二烯的主要形成归因于来自蓝色LED的有效可见光照明,以及可能的从光敏剂CN-TPT到E-异构体的能量转移。