...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Catalysis science & technology >The iso-VAPOL ligand: synthesis, solid-state structure and its evaluation as a BOROX catalyst
【24h】

The iso-VAPOL ligand: synthesis, solid-state structure and its evaluation as a BOROX catalyst

机译：ISO-VAPOL配体：合成，固态结构及其作为硼催化剂的评估

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The new vaulted biaryl ligand iso-VAPOL is an isomer of VAPOL but has the chiral pocket of VANOL. The synthesis of iso-VAPOL involves a cycloaddition/electrocyclization cascade (CAEC) similar to one that is used for VAPOL except that the starting material for iso-VAPOL is less than one-tenth the cost. The solid-state structure of iso-VAPOL was determined as well as that of VANOL since it had not been previously reported. The structures of iso-VAPOL and VANOL are compared to the known solid-state structure of VAPOL and it is found that all three ligands have the cisoid conformations in the solid-state; the dihedral angle between the two aryl groups is less than 90 degrees. In addition, all three ligands pack in the solid-state with no inter-molecular hydrogen bonds. This is the opposite to what has been reported for BINOL where all known structures exist with transoid conformations where the dihedral angle is >90 degrees and where the BINOL units pack with hydrogen bonds between neighboring BINOL units. Spectroscopic evidence including H-1 and B-11 NMR spectra are presented which indicate that the iso-VAPOL ligand will form BOROX catalysts with B(OPh)(3) in much the same way as VAPOL catalysts which have previously reported and characterized both by spectroscopy and X-ray crystallography. Support for the BOROX catalysts can also be taken from the fact that iso-VAPOL BOROX catalysts give essentially the same asymmetric inductions as the VAPOL BOROX catalyst over a range of substrates.
机译：新的拱形双子体配体ISO-VAPOL是Vapol的异构体，但有Vanol的手性袋。 ISO-VAPOL的合成涉及类似于用于Vapol的级联/电气环化级联反应（CAEC），只是ISO-VAPOL的起始材料不到成本的十分之一。由于没有以前没有报道，因此确定了ISO-VAPOL的固态结构以及Vanol的结构。将ISO-VAPOL和VANOL的结构与Vapol的已知固态结构进行了比较，发现所有三种配体在固态中均具有Cisoid构象。两个芳基之间的二面角小于90度。此外，所有三个配体都包装在固态中，没有分子间氢键。这与Binol报道的相反，在Binol中，所有已知的结构都具有二面角> 90度的经织物构象，而Binol单元在相邻的Binol单元之间包装了二醇单元。提出了包括H-1和B-11 NMR光谱在内的光谱证据，表明ISO-VAPOL配体将以B（OPH）（3）的方式形成与先前已经报告和表征的Vapol催化剂的Borox催化剂（OPH）（3）（3）。光谱和X射线晶体学。还可以从以下事实中获取对硼型催化剂的支持：Iso-Vapol Borox催化剂基本上具有与一系列底物上的Vapol Borox催化剂相同的不对称诱导。

著录项

相似文献

  • 外文文献
  • 中文文献
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号