Asymmetric Borane Reduction of Prochiral Ketones Catalyzed By Helical Poly[(S)-3-vinyl-2,2'-dihydroxy-1,1'-binaphthyl]
作者:Guochang Qin、Yehui Chen、Liwen Yang、Nianfa Yang、Zhusheng Yang
DOI:10.1002/chir.22459
日期:2015.7
The application of helical poly[(S)‐3‐vinyl‐2,2'‐dihydroxy‐1, 1'‐binaphthyl] (L*) in the asymmetric borane reduction of prochiral ketones was studied. The results showed that L* had excellent catalytic activity as well as enantioselectivity, giving up to 96% yield and up to 99% enantiomeric excess (ee) of the corresponding secondary alcohol at 25 °C. Moreover, L* can be easily recovered and reused
Optically Active Helical Polymer from Radical Polymerization of (<i>S</i>)-3-Vinyl-2,2′-dihydroxy-1,1′-binaphthyl
作者:Yehui Chen、Liwen Yang、Nianfa Yang、Zhusheng Yang
DOI:10.1246/cl.140755
日期:2014.11.5
(S)-3-Vinyl-2,2′-dihydroxy-1,1′-binaphthyl (2) was radically polymerized to obtain a polymer with excess of preferred-handed helical sense. The specific optical rotation [α]36525 of poly-2 was −1364.2° and more than 4 times that of starting monomer 2. Poly-2 was confirmed to exist in the form of preferred-handed helical structure in solution by means of comparing the specific optical rotation, the circular dichroism (CD) and ultraviolet–visible (UV–vis) spectra with that of 2 and the model compound such as (S)-3-ethyl-2,2′-dihydroxy-1,1′-binaphthyl (3).