Visible Light-Promoted Synthesis of Spiroepoxy Chromanone Derivatives via a Tandem Oxidation/Radical Cyclization/Epoxidation Process
作者:Sungwoo Jung、Jiyun Kim、Sungwoo Hong
DOI:10.1002/adsc.201701072
日期:2017.11.23
A highly efficient and straightforward approach for the synthesis of spiroepoxy chroman‐4‐one derivatives was developed using a visible light‐enabled tandem radical strategy. The reaction is initiated by the formation of an acyl radical that undergoes intramolecularradical cyclization and epoxidation. The optimal result was obtained with 1 mol% of Ru(bpy)3Cl2⋅6H2O, TBHP, and K2CO3 in i‐PrOAc at room
使用可见光启用的串联自由基策略开发了一种高效且直接的合成螺环氧基苯并吡喃-4-酮衍生物的方法。通过形成经历分子内自由基环化和环氧化的酰基自由基来引发反应。用1mol%的Ru获得的最优结果(BPY)3氯2 ⋅6H 2 O,TBHP,和K 2 CO 3在我-PrOAc在室温下与来自蓝色LED照射。这种前所未有的串联方法利用了广泛的底物,并提供了一种方便而强大的合成工具,可用于获得合成上有用的螺环苯并二氢吡喃-4-酮及其含氮衍生物。
Vanillin and o-vanillin oligomers as models for dendrimer disassembly
作者:Robert M. Kevwitch、Charles S. Shanahan、Dominic V. McGrath
DOI:10.1039/c1nj20841a
日期:——
Linear analogs have been synthesized to model disassembling dendrimers. These linear analogs provide a facile synthesis to molecules that can be used to test new trigger groups and cleavage vectors. Vanillin and o-vanillin were used as the monomer units of these analogs and two trigger groups, allyl and o-nitrobenzyl, were chosen to test the disassembly process. Allyl triggered analogs 1a–d and 3a–d and o-nitrobenzyl triggered analogs 2a–c and 4a–c showed good to excellent disassembly as followed by the evolution of p-nitrophenoxide reporter ion by UV-Visible spectroscopy. The rate and yield of disassembly was shown to depend on experimental conditions as well as length of the cleavage vector.