A new chiral dithiol is used to bridge Au25 nanoclusters together. Due to its bidentate nature, the dimers and trimers can be isolated before further reaction occurs. The structure of the oligomers is analysed by small-angle X-ray spectroscopy. The changes in optical properties are followed by UV/Vis absorption, fluorescence spectroscopy and circular dichroism.
一种新的手性二硫醇用于将 Au 25纳米团簇桥接在一起。由于其双齿性质,二聚体和三聚体可以在进一步反应发生之前分离。通过小角 X 射线光谱分析低聚物的结构。光学性质的变化之后是 UV/Vis 吸收、荧光光谱和圆二色性。
Self-supported BINOL–Zn catalysts for heterogeneous enantioselective epoxidation of (E)-α,β-unsaturated ketones
作者:Haiming Wang、Zheng Wang、Kuiling Ding
DOI:10.1016/j.tetlet.2009.02.151
日期:2009.5
A class of chiral self-supported catalysts prepared from bis-BINOL ligands and diethyl zinc were successfully applied in the hetereogeneous enantioselective epoxidation of a range of (E)-alpha,beta-unsaturated ketones, affording the corresponding epoxy ketones in high enantioselectivity. The self-supported catalysts were easily recovered from the reaction mixture and were reusable for several consecutive runs. (C) 2009 Elsevier Ltd. All rights reserved.