possessed stable chirality despite flexible biphenyl structures because of the high strain in the diethynyl–paraphenylene moiety. In both the single and double CPEs, orbital interactions along the biphenyl axis were observed by DFT calculations in LUMO and LUMO+2 of the single CPE and LUMO+1 of the double CPE, which likely cause lowering of these orbital energies. Concerning chiropticalproperties: boosting
Enantioseparation and Electronic Properties of a Propeller-Shaped Triarylborane
作者:Hiroshi Ito、Takanori Abe、Kazuhiko Saigo
DOI:10.1002/anie.201101406
日期:2011.7.25
Flip out! Bulky substituents induce a high barrier to interconversion of the helically chiral enantiomers of the title triarylborane (see picture) and thus allow the separation of the enantiomers by chiral chromatography. The electronicproperties of the central boron atom play a significant role in the flipping dynamics of the propeller structure, and racemization can be greatly accelerated by UV‐light