A general and practical process for the conversion of prochiral ketones into the corresponding chiral acetates has been realized. An iron carbonyl complex is reported to catalyze the hydrogenation–dehydrogenation–hydrogenation of prochiral ketones. By merging the iron‐catalyzed redox reactions with enantioselective enzymatic acylations a wide range of benzylic, aliphatic and (hetero)aromatic ketones
Ruthenium- and Enzyme-Catalyzed Dynamic Kinetic Resolution of Secondary Alcohols
作者:B. Anders Persson、Anna L. E. Larsson、Mikaël Le Ray、Jan-E. Bäckvall
DOI:10.1021/ja983819+
日期:1999.3.1
Enzymaticresolution of secondary alcohols under substrate racemizing conditions was studied using an immobilized lipase from Candida antarctica in the presence of a ruthenium catalyst. A specifically designed acyldonor, 4-chlorophenyl acetate, was found to be compatible with both catalysts and resulted in an efficient dynamic kinetic resolution. Studies of the reaction in different solvents showed
在钌催化剂存在下,使用来自南极念珠菌的固定化脂肪酶研究了底物外消旋条件下仲醇的酶促拆分。发现专门设计的酰基供体 4-氯苯乙酸酯与两种催化剂均相容,并导致有效的动态动力学拆分。在不同溶剂中的反应研究表明,非极性溶剂的结果最好。通过该过程,各种外消旋仲醇转化为相应的对映异构纯乙酸酯,有效利用所有原材料。在大多数情况下,反应以 >99% ee 和良好的收率进行。
On the Mechanism of the Unexpected Facile Formation of <i>m</i><i>eso</i>-Diacetate Products in Enzymatic Acetylation of Alkanediols
作者:Michaela Edin、Jan-E. Bäckvall
DOI:10.1021/jo026652i
日期:2003.3.1
the enzymaticresolution of dl/meso mixtures of 2,4-pentanediol and 2,5-hexanediol with Candida antarctica lipase B has been elucidated. It was found that the formation of meso-diacetate proceeds via different mechanisms for the two diols. Enzyme-catalyzed acylation of AcO-d(3) labeled (R)-monoacetates of meso-2,4-pentanediol and meso-2,5-hexanediol and analysis of the meso-diacetates obtained show
Dynamic Kinetic Resolution of Secondary Diols via Coupled Ruthenium and Enzyme Catalysis
作者:B. Anders Persson、Fernando F. Huerta、Jan-E. Bäckvall
DOI:10.1021/jo990447u
日期:1999.7.1
Enzymatic acylation of secondary symmetrical diols (as meso/dlmixtures) in combination with ruthenium-catalyzed isomerization of the diol led to efficient dynamic kineticresolution. In this way, a meso/dlmixture of the diol was transformed to enantiomerically pure (R,R)-diacetate, making efficient use of all the diol material. For some of the flexible substrates, substantial amounts of meso-diacetates
Dynamic kinetic asymmetric transformation of 1,4-diols and the preparation of trans-2,5-disubstituted pyrrolidines
作者:Linnéa Borén、Karin Leijondahl、Jan-E. Bäckvall
DOI:10.1016/j.tetlet.2009.02.079
日期:2009.7
Dynamic kinetic asymmetric transformation (DYKAT) of a series of 1,4-diols is carried out with Candida antarctica lipase B (CALB), Pseudomonas cepacia lipase II (PS-C II), and a ruthenium catalyst. A β-chloro-substituted 1,4-diol is successfully transformed into an optically pure 1,4-diacetate, which is a highly useful synthetic intermediate. The usefulness of the optically pure 1,4-diacetates is demonstrated