Synthesis and Fluorescence Properties of Novel Pyrazine–Boron Complexes Bearing a β-Iminoketone Ligand
摘要:
A novel fluorescence dye based on pyrazine-boron complexes bearing a beta-iminoketone ligand has been synthesized by using a simple two-step reaction. Synthesized complexes exhibited fluorescence in solution (F-max: 472-604 nm) and in the solid state (F-max: 496-624 nm). These complexes showed a larger Stokes shift(3690-4900 cm(-1)) than well-known boron dipyrromethene dyes (400-600 cm(-1), in most cases).
Iridium-Catalyzed Intramolecular Asymmetric Allylic Dearomatization Reaction of Pyridines, Pyrazines, Quinolines, and Isoquinolines
作者:Ze-Peng Yang、Qing-Feng Wu、Wen Shao、Shu-Li You
DOI:10.1021/jacs.5b10440
日期:2015.12.23
The first Ir-catalyzed intramolecularasymmetricallylicdearomatization reaction of pyridines, pyrazines, quinolines, and isoquinolines has been developed. Enabled by in situ formed chiral Ir-catalyst, the dearomatized products were isolated in high levels of yield (up to 99% yield) and enantioselectivity (up to 99% ee). It is worth noting that the Me-THQphos ligand is much more efficient than other
已开发出第一个 Ir 催化的吡啶、吡嗪、喹啉和异喹啉的分子内不对称烯丙基脱芳构化反应。通过原位形成的手性 Ir 催化剂,脱芳构化产物以高产率(高达 99% 的产率)和对映选择性(高达 99% ee)分离。值得注意的是,对于吡嗪和某些喹啉的脱芳构化,Me-THQphos 配体比其他测试的配体更有效。进行了脱芳构化反应的机理研究,结果表明了以形成喹啉作为关键中间体的替代方法的可行性。机理研究结果使该反应成为 Reissert 型反应化学中尚不为人知的类型。此外,