Catalytic enantioselective syn hydration of enones in water using a DNA-based catalyst
摘要:
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。
Supramolecular Assembly of Artificial Metalloenzymes Based on the Dimeric Protein LmrR as Promiscuous Scaffold
作者:Jeffrey Bos、Wesley R. Browne、Arnold J. M. Driessen、Gerard Roelfes
DOI:10.1021/jacs.5b05790
日期:2015.8.12
to a protein scaffold is an attractive approach to the construction of artificialmetalloenzymes since this is conveniently achieved by self-assembly. Here, we report a novel design for supramolecular artificialmetalloenzymes that exploits the promiscuity of the central hydrophobic cavity of the transcription factor Lactococcal multidrug resistance Regulator (LmrR) as a generic binding site for planar
Using the DNA-based catalysis concept, a novel Cu(ii) catalyzed enantioselective oxa-Michael addition of alcohols to enones is reported. Enantioselectivities of up to 86% were obtained. The presence of water is important for the reactivity, possibly by reverting unwanted side reactions such as 1,2-additions.
Organic co-solvents in aqueous DNA-based asymmetric catalysis
作者:Rik P. Megens、Gerard Roelfes
DOI:10.1039/b921385f
日期:——
Water-miscible organic co-solvents can be used in DNA-based catalytic asymmetric reactions at appreciable concentration without a negative effect on enantioselectivity. While the rate of the copper(II) Diels–Alder reaction is affected negatively by the presence of organic co-solvents, the copper(II) catalyzed Michael addition and Friedel–Crafts alkylation reaction are significantly faster. Additionally
On the Role of DNA in DNA-based Catalytic Enantioselective Conjugate Addition Reactions
作者:Ewold W. Dijk、Arnold J. Boersma、Ben L. Feringa、Gerard Roelfes
DOI:10.1039/c005048b
日期:——
A kinetic study of DNA-based catalyticenantioselective Friedel–Crafts alkylation and Michael additionreactions showed that DNA affects the rate of these reactions significantly. Whereas in the presence of DNA, a large acceleration was found for the Friedel–Crafts alkylation and a modest acceleration in the Michael addition of dimethyl malonate, a deceleration was observed when using nitromethane