Efficient methodology to produce a duloxetine precursor using whole cells of Rhodotorula rubra
摘要:
Different types of yeasts were employed as biocatalysts in the reduction of beta-ketonitriles. The red microorganism, Rhodotorula rubra, was selected as the best performing catalyst in the reduction of different substituted ketonitriles giving total stereoselectivity in most cases (90-99% ee). In particular, its use as fresh and lyophilised cells was expanded to a semi-preparative scale for the production of the duloxetine precursor 1a, R. rubra was screened in the reduction of alkylation products in comparison with Pichia henricii for assignment of configuration of products 2a and 11a after derivatisation with S-MPA. (C) 2016 Published by Elsevier Ltd.
IBX-Mediated Dehydrogenation of Substituted β-Oxonitriles
作者:Philipp Klahn、Stefan F. Kirsch
DOI:10.1002/ejoc.201402007
日期:2014.5
convenient method for the mild dehydrogenation of β-oxonitriles is presented. When treated with o-iodoxybenzoic acid (IBX), a range of these compounds were transformed into their unsaturated counterparts. Furthermore, we show that the products of the dehydrogenation can react in situ, undergoing rapid hetero-Diels–Alder reactions with enol ethers to give multiply substituted dihydropyrans. We also describe
Different types of yeasts were employed as biocatalysts in the reduction of beta-ketonitriles. The red microorganism, Rhodotorula rubra, was selected as the best performing catalyst in the reduction of different substituted ketonitriles giving total stereoselectivity in most cases (90-99% ee). In particular, its use as fresh and lyophilised cells was expanded to a semi-preparative scale for the production of the duloxetine precursor 1a, R. rubra was screened in the reduction of alkylation products in comparison with Pichia henricii for assignment of configuration of products 2a and 11a after derivatisation with S-MPA. (C) 2016 Published by Elsevier Ltd.
Oxidative Chlorination of Activated Methylene Compounds with Sodium Chloride
An operationally simple protocol for the direct chlorination of 1,3-dicarbonyls (and related compounds such as α-cyano ketones) is described. The procedure relies on mild conditions using IBX–SO 3 K as the stoichiometric oxidizing agent and the ubiquitous sodium chloride. The presence of a phase-transfer catalyst is supportive to obtain good yields in a THF–water mixture.
描述了一种用于直接氯化 1,3-二羰基化合物(和相关化合物,如 α-氰基酮)的操作简单的协议。该过程依赖于使用 IBX-SO 3 K 作为化学计量氧化剂和无处不在的氯化钠的温和条件。相转移催化剂的存在有助于在 THF-水混合物中获得良好的产率。