958-06-5Relevant articles and documents
Electronic Effect-Guided Rational Design of Candida antarctica Lipase B for Kinetic Resolution Towards Diarylmethanols
Li, Dan-Yang,Lou, Yu-Jiao,Xu, Jian,Chen, Xiao-Yang,Lin, Xian-Fu,Wu, Qi
supporting information, p. 1867 - 1872 (2021/02/12)
Herein, we developed an electronic effect-guided rational design strategy to enhance the enantioselectivity of Candida antarctica lipase B (CALB) mutants towards bulky pyridyl(phenyl)methanols. Compared to W104A mutant previously reported with reversed S-stereoselectivity toward sec-alcohols, three mutants (W104C, W104S and W104T) displayed significant improvement of S-enantioselectivity in the kinetic resolution (KR) of various phenyl pyridyl methyl acetates due to the increased electronic effects between pyridyl and polar residues. The electronic effects were also observed when mutating other residues surrounding the stereospecificity pocket of CALB, such as T42A, S47A, A281S or A281C, and can be used to manipulate the stereoselectivity. A series of bulky pyridyl(phenyl) methanols, including S-(4-chlorophenyl)(pyridin-2-yl) methanol (S-CPMA), the intermediate of bepotastine, were obtained in good yields and ee values. (Figure presented.).
Synthesis and characterization of ionic liquid immobilized on magnetic nanoparticles: A recyclable heterogeneous organocatalyst for the acetylation of alcohols
Ghorbani-Choghamarani, Arash,Norouzi, Masoomeh
, p. 832 - 840 (2015/11/16)
Herein, we describe a simple and efficient procedure for the preparation of 3-((3-(trisilyloxy)propyl)propionamide)-1-methylimidazolium chloride ionic liquid supported on magnetic nanoparticle (TPPA-IL-Fe3O4). The structure of this magnetic ionic liquid is fully characterized by FT-IR, TGA, XRD, VSM, SEM, EDX and DLS techniques. TPPA-IL-Fe3O4 is employed as a catalyst for the acetylation of alcohols with acetic anhydride under mild and heterogeneous conditions at room temperature with good to excellent yields. The magnetic catalyst could be readily separate from the reaction media by simple magnetic decantation, and reused several times without significant loss of its catalytic activity.
DDQ-catalyzed oxidative C-O coupling of sp3 C-H bonds with carboxylic acids
Yi, Hong,Liu, Qiang,Liu, Jie,Zeng, Ziqi,Yang, Yuhong,Lei, Aiwen
, p. 2143 - 2146 (2013/01/15)
Da-ddy, DDQ: By using catalytic amounts of DDQ combined with MnO 2 as oxidant, an efficient oxidative C-O coupling of benzylic sp 3 C-H bonds with carboxylic acids affords a series of carboxylic esters in 70-98 % yields. A wide range