Catalytic enantioselective syn hydration of enones in water using a DNA-based catalyst
作者:Arnold J. Boersma、David Coquière、Danny Geerdink、Fiora Rosati、Ben L. Feringa、Gerard Roelfes
DOI:10.1038/nchem.819
日期:2010.11
The enantioselective addition of water to olefins in an aqueous environment is a common transformation in biological systems, but was beyond the ability of synthetic chemists. Here, we present the first examples of a non-enzymatic catalytic enantioselective hydration of enones, for which we used a catalyst that comprises a copper complex, based on an achiral ligand, non-covalently bound to (deoxy)ribonucleic acid, which is the only source of chirality present under the reaction conditions. The chiral β-hydroxy ketone product was obtained in up to 82% enantiomeric excess. Deuterium-labelling studies demonstrated that the reaction is diastereospecific, with only the syn hydration product formed. So far, this diastereospecific and enantioselective reaction had no equivalent in conventional homogeneous catalysis. Nature frequently shows exquisite control over reactions both of water and in water. Here, the enantioselective conjugate addition of water to an enone â a reaction that has no equivalent in conventional homogeneous catalysis â is catalysed by a copper complex of an achiral ligand that is non-covalently bound to DNA.
在水环境中水与烯烃的对映体选择性加成是生物系统中常见的转化过程,但合成化学家却无法做到。在这里,我们首次展示了烯酮的非酶催化对映体选择性水合反应,为此我们使用了一种催化剂,该催化剂由基于非手性配体的铜络合物组成,铜络合物与(脱氧)核糖核酸非共价结合,而核糖核酸是反应条件下存在的唯一手性来源。手性δ-羟基酮产品的对映体过量率高达 82%。氘标记研究表明,该反应具有非对映特异性,只形成了同步水合产物。迄今为止,这种非对映专一性和对映体选择性反应在传统的均相催化反应中还没有出现过。大自然经常对水和水中的反应进行精妙的控制。在这里,水与烯酮的对映选择性共轭加成反应是由非共价结合到 DNA 上的非手性配体的铜络合物催化的。