138309-06-5Relevant academic research and scientific papers
Resolution of (R,S)-1-(4-methoxyphenyl)ethanol by lipase-catalyzed stereoselective transesterification and the process optimization
He, Bingbing,Tang, Fengci,Sun, Chenrui,Su, Jiahao,Wu, Bingcheng,Chen, Yan,Xiao, Yuquan,Zhang, Panliang,Tang, Kewen
, p. 438 - 445 (2021/12/17)
An efficient lipase-catalyzed stereoselective transesterification reaction system was established for resolution of 1-(4-methoxyphenyl)ethanol (MOPE) enantiomers. A series of lipases were tested and compared. The immobilized lipase Novozym 40086 is selected as the best choice. The effects of organic solvent, acyl donor, time and temperature on substrate conversion (c), and optical purity of the remaining substrate (eeS) were investigated. Response surface methodology and central composite design were employed to evaluate the effect of some important factors and to optimize the process. Under the optimized conditions including solvent of n-hexane, acyl donor of vinyl acetate, temperature of 35°C, substrate molar ratio of 1:6, enzyme dosage of 20 mg, and reaction time of 2.5 h, eeS of 99.87% with c of 56.71% is achieved. The use of alkane solvent and immobilized enzyme, the mild reaction conditions, and the reduced reaction time make the system promising in industrial application.
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
supporting information, 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.
Structure-enantioselectivity effects in 3,4-dihydropyrimido[2,1-b] benzothiazole-based isothioureas as enantioselective acylation catalysts
Belmessieri, Dorine,Joannesse, Caroline,Woods, Philip A.,MacGregor, Callum,Jones, Caroline,Campbell, Craig D.,Johnston, Craig P.,Duguet, Nicolas,Concellon, Carmen,Bragg, Ryan A.,Smith, Andrew D.
scheme or table, p. 559 - 570 (2011/03/16)
The catalytic activity and enantioselectivity in the kinetic resolution of (±)-1-naphthylethanol with a range of structurally related 3,4-dihydropyrimido[2,1-b]benzothiazole-based catalysts is examined. Of the isothiourea catalysts screened, (2S,3R)-2-phenyl-3-isopropyl substitution proved optimal, giving good levels of selectivity in the kinetic resolution of a number of secondary alcohols (S values up to >100 at ～50% conversion). Low catalyst loadings (0.10-0.25 mol%) of the optimal isothiourea can be used to generate enantiopure alcohols (>99% ee) in good yields.
A highly selective ferrocene-based planar chiral PIP (Fc-PIP) acyl transfer catalyst for the kinetic resolution of alcohols
Hu, Bin,Meng, Meng,Wang, Zheng,Du, Wenting,Fossey, John S.,Hu, Xinquan,Deng, Wei-Ping
supporting information; experimental part, p. 17041 - 17044 (2011/02/16)
Novel planar chiral ferrocene nucleophilic catalysts (Fc-PIP) containing both central and planar chiral elements were designed and synthesized for catalytic enantioselective acyl transfer of secondary alcohols. A remarkably efficient catalyst with high selectivity factors (up to S = 1892) was identified. Comparing the combination of central and planar chirality revealed a strong requirement for the "matched" chiral elements, indicating that the stereogenic center of the imidazole rings should present itself on the same face as the ferrocenyl fragment; otherwise, the catalyst is completely inactive. An exclusively stacked transition state that accounts for the high selectivity of the kinetic resolution of secondary alcohols is proposed. Notably, this newly designed catalyst family is suitable for the catalytic kinetic resolution of bulky arylalkyl carbinols, producing esters with extremely high ee (>99%).
