133082-13-0Relevant articles and documents
Highly Efficient Synthesis of Optically Pure (S)-1-phenyl-1,2-ethanediol by a Self-Sufficient Whole Cell Biocatalyst
Chen, Xi,Mei, Ting,Cui, Yunfeng,Chen, Qijia,Liu, Xiangtao,Feng, Jinhui,Wu, Qiaqing,Zhu, Dunming
, p. 483 - 488 (2015)
Terminal vicinal diols are important chiral building blocks and intermediates in organic synthesis. Reduction of α-hydroxy ketones provides a straightforward approach to access these important compounds. In this study, it has been found that asymmetric reduction of a series of α-hydroxy aromatic ketones and 1-hydroxy-2-pentanone, catalyzed by Candida magnolia carbonyl reductase (CMCR) with glucose dehydrogenase (GDH) from Bacillus subtilis for cofactor regeneration, afforded 1-aryl-1,2-ethanediols and pentane-1,2-diol, respectively, in up to 99 % ee. In order to evaluate the efficiency of the bioreduction, lyophilized recombinant Escherichia coli whole cells coexpressing CMCR and GDH genes were used as the biocatalyst and α-hydroxy acetophenone as the model substrate, and the reaction conditions, such as pH, cosolvent, the amount of biocatalyst and the presences of a cofactor (i.e., NADP+), were optimized. Under the optimized conditions (pH6, 16h), the bioreduction proceeded smoothly at 1.0 m substrate concentration without the external addition of cofactor, and the product (S)-1-phenyl-1,2-ethanediol was isolated with 90 % yield and 99 % ee. This offers a practical biocatalytic method for the preparation of these important vicinal diols. Self-sufficient catalysis! Lyophilized recombinant Escherichia coli coexpressing Candida magnolia carbonyl reductase (CMCR) and glucose dehydrogenase (GDH) genes served as an effective self-sufficient biocatalyst for the reduction of α-hydroxy acetophenones at high substrate concentrations. The products were isolated with high yield and excellent optical purity, offering a practical biocatalytic method for the preparation of vicinal diols.
Selective monochlorination of unsymmetrical vicinal diols with chlorinated iminium chlorides
Li, Chengyang,Li, Xiaotong,Wang, Yu,Wu, Xiaoyu,Xie, Xiaomin,Yang, Liqun,Zhang, Zhaoguo
supporting information, (2020/03/23)
Chlorinated iminium chlorides have been identified to promote the highly efficient and selective mono-chlorination of unsymmetrical vicinal diols. Vilsmeier reagent, namely, (chloromethylene)dimethyliminium chloride, enables highly reactive and regioselective chlorination of 1,2- and 1,3-diols featured one secondary benzylic hydroxy group and one primary aliphatic hydroxy group to give the corresponding 1,2- and 1,3-chlorohydrins. Viehe's salts (α,α-dichloro iminium salts) exhibit excellent reactivity and good selectivity for vicinal diols to give the corresponding chlorohydrin carbamates via a cyclic intermediate in situ. The chlorination protocols tolerate diverse functional groups, including halogens, naphthalene rings, nitro, and cyano. Moreover, the optical purity of chiral diols could be retained during this chlorination reaction.
Transition-Metal-Free Stereospecific Cross-Coupling with Alkenylboronic Acids as Nucleophiles
Li, Chengxi,Zhang, Yuanyuan,Sun, Qi,Gu, Tongnian,Peng, Henian,Tang, Wenjun
supporting information, p. 10774 - 10777 (2016/09/09)
We herein report a transition-metal-free cross-coupling between secondary alkyl halides/mesylates and aryl/alkenylboronic acid, providing expedited access to a series of nonchiral/chiral coupling products in moderate to good yields. Stereospecific SN2-type coupling is developed for the first time with alkenylboronic acids as pure nucleophiles, offering an attractive alternative to the stereospecific transition-metal-catalyzed C(sp2)-C(sp3) cross-coupling.
