An efficient 1,7-asymmetricinduction was achieved with up to 82% diastereoisomeric excess (d.e.) in the diastereoselective reduction of the γ-keto ester 4 and o-acetylbenzoate 6 using the chiral podand 2 as chiral auxiliary.
Effects of terminal chain length in hydrogen-bonded chiral switches on phototunable behavior of chiral nematic liquid crystals: helicity inversion and phase transition
作者:Dengwei Fu、Juntao Li、Jie Wei、Jinbao Guo
DOI:10.1039/c5sm00128e
日期:——
series of photoresponsive chiralswitches are fabricated by a facile hydrogen-bonded (H-bonded) assembly method, in which the binaphthyl azobenzene molecule is used as the proton acceptor, and binaphthyl acids with opposite chiral configuration are proton donors. We find that the helicaltwistedpower of H-bonded chiralswitches and the helical handedness of induced chiral nematic liquid crystals (N*-LCs)
Pseudo-macrocyclic chelation control in remote asymmetric induction. Highly efficient 1,7-asymmetric inductive hydride reduction and Grignard reaction of γ-keto esters of 1,1′-binaphthalen-2-ols bearing an appropriate oligoether group as the 2′-substituent
Highly efficient 1,7-asymmetricinduction was achieved in DIBAL-H reduction and Grignard reaction of γ-keto esters of podand-type 1,1′-binaphthalen-2-ol derivatives bearing an appropriate oligoether group as the 2′-substituent. Thus, the DIBAL-H reduction of keto esters 4 in dichloromethane–toluene at –78 °C in the presence of an excess of MgBr2·OEt2 afforded, after further reduction of the resulting
Irradiation‐Wavelength Directing Circularly Polarized Luminescence in Self‐Organized Helical Superstructures Enabled by Hydrogen‐Bonded Chiral Fluorescent Molecular Switches
作者:Yanrong He、Shu Zhang、Hari Krishna Bisoyi、Jinghui Qiao、Hong Chen、JingJing Gao、Jinbao Guo、Quan Li
DOI:10.1002/anie.202111344
日期:2021.12.20
turning-off and the polarization inversion of circularlypolarizedluminescence signals is obtained in the corresponding photostationary state of the same helical cholesteric superstructure constructed from the light-driven hydrogen bonded chiral fluorescent molecular switch, which derives from the different conversion ratio of Z/E photoisomerization of the switch upon different light irradiations.