Diastereomers of a cofacial ternaphthalene and two azaternaphthalenes. Syntheses and barriers to isomerization
作者:John A. Zoltewicz、Norbert M. Maier、Sophie Lavieri、Ion Ghiviriga、Khalil A. Abboud、Walter M.F. Fabian
DOI:10.1016/s0040-4020(97)00232-9
日期:1997.4
The title compounds, a mixture of anti and syn diastereomers, were prepared by Pd-catalyzed coupling of areneboronic acids with hetaryl halides. Energy barriers for the interconversion of the diastereomers obtained by kinetic and computational studies show a dependence on the location of the annular nitrogen atom, the ortho providing a smaller barrier than the meta nitrogen atom.
synthetic protocol to prepare fused six‐memberedphosphorusheterocycles. In particular, we report the synthesis of novel phosphaphenalenes. These fused systems exhibit the benefits of both five‐ and six‐memberedphosphorusheterocycles and enable a series of versatile postfunctionalization reactions. This work thus opens up new horizons in the field of conjugated materials.
This work presents the first enantio- and diastereoselectiveassembly of multi-layer folding targets through asymmetric catalytic C-C bond formation. Pd[(S)-BINAP]Cl2 was found to be an efficient catalyst for Suzuki-Miyaura coupling between phosphinyl bromides and benzo thiadiazole boronic esters for this asymmetric assembly. The resulting chiral multi-layer folding framework was unambiguously determined
这项工作提出了第一个通过不对称催化 CC 键形成的多层折叠目标的对映和非对映选择性组装。Pd[(S)-BINAP]Cl2 被发现是用于此不对称组装的膦酰溴和苯并噻二唑硼酸酯之间的 Suzuki-Miyaura 偶联的有效催化剂。由此产生的手性多层折叠框架通过 X 射线结构分析明确确定,显示出三层几乎平行的模式以及准同步和反配置。已经实现了良好到优秀的非对映和对映选择性(高达 > 20:1 dr 和 > 99:1 er)。