A practical chemical synthesis of L-camitine （1） has been accomplished from （R）-3-chloro-1,2-propanediol （（R）-4）, which is a main by-product originated from （R,R）-Salen Co（III） catalyzed hydrolytic kinetic resolution （HKR） of （±）-epichlorohydrin. （R）-4 was utilized as a chiral starting material to prepare the key intermediate cyclic sulfite （（R）-S）. The new synthetic approach demonstrated an efficient utilization of organic by-product for the asymmetric synthesis of bioactive compounds.
Xu Qin Li Yun Xu Yang Wei Li Wang Bin Hu Hui Min Xue Tian Yi Zhang Xue Tao Zhang
A simple 8-quinolinecarboxaldehyde derived antipyrine Schiff base （QA） was synthesized and characterized, which exhibited high selectivity to Cr^3＋ over other metal cations. The Cr^3＋ recognition of QA could be achieved by means of fluorescense and absorption spectra, moreover, the obvious color change from colorless to yellowish is easily observed by naked-eyes. The binding constant of QA to Cr^3＋ was evaluated by spectral titration and the binding model was in 1 ： 1 stoichiometry measured by Job＇s plot.
Yunxu YangHuimin XueLaicheng ChenRuilong ShengXuqin LiKun Li
