35279-24-4Relevant academic research and scientific papers
Base-catalyzed selective esterification of alcohols with unactivated esters
Zhang, Chunyan,Zhang, Guoying,Luo, Shizhong,Wang, Chunfu,Li, Huiping
supporting information, p. 8467 - 8471 (2018/12/01)
A practical and efficient base-catalyzed esterification has been developed for the facile synthesis of a broad range of esters from simple alcohols with unactivated tert-butyl esters. This protocol could be conducted at mild conditions, providing esters in high to excellent yields with good functional tolerance. Mechanistic studies provided evidence of an exchange of the tert-butyl alkoxide metal with the alcohol, producing a new alkoxide to participate in the transesterification reaction.
Dynamic double kinetic resolution of amines and alcohols under the cocatalysis of Raney nickel/Candida antarctica lipase B: From concept to application
Xia, Bo,Cheng, Guilin,Lin, Xianfu,Wu, Qi
, p. 2917 - 2923 (2014/05/20)
Herein, we have established a dynamic double kinetic resolution (DDKR) strategy under the co-catalysis of Raney nickel and Candida antarctica lipase B (CAL-B) for the one-pot simultaneous resolution of primary amines and secondary alcohols (or esters). The DDKR strategy was successfully applied to the resolution of a series of racemic amines and secondary alcohols (or esters) as well as mexiletine, an important antiarrhythmic agent. The catalysts could be recycled and reused several times with the same high activity. Scale-up experiments were also successful. As a more atom-economical and efficient process than traditional simple kinetic resolutions, the DDKR strategy can be widely used to prepare optically pure amines and alcohols.
Kinetic studies on sec-alcohol racemization with dicarbonylchloro(pentabenzylcyclopentadienyl)- and dicarbonylchloro(pentaphenylcyclopentadienyl)ruthenium catalysts
Mavrynsky, Denys,Murzin, Dmitry Yu.,Leino, Reko
, p. 2436 - 2445 (2013/08/23)
Pentasubstituted cyclopentadienyl complexes of ruthenium R5CpRu(CO)2Cl (R=Ph, benzyl) form, upon activation with tBuOK, highly active catalysts for racemization of chiral sec-alcohols. In combination with suitable resolving enzymes, such catalyst systems can efficiently be utilized for dynamic kinetic resolution reactions providing chiral alcohols, after hydrolysis of the corresponding acetates, in high yields and high enantiomeric purities. Here, three such ruthenium complexes were first characterized by NMR spectroscopy and cyclic voltammetry analysis (CVA) for elucidating their electronic characteristics in detail. Then, accurate kinetic studies were performed providing for the first time the calculated racemization rate constants for such catalyst systems. Furthermore, the dependence of the racemization rate on the electronic structure of the catalyst was investigated from the Hammett constants, substitution patterns of the substrate, and by isotopic labeling studies. The results obtained support the earlier suggested racemization reaction mechanism and indicated that the electron-rich catalyst Bn5CpRu(CO)2Cl (Bn=benzyl) racemizes electron-rich substrates more efficiently and in most cases faster than its pentaphenyl substituted analogue, formerly often considered as the leading catalyst candidate for dynamic kinetic resolution applications. The electron-deficient catalyst Ph5CpRu(CO)2Cl, in turn, is more efficient for electron-poor substrates.
