介绍了一系列新型有机催化剂的设计、制备和研究。催化剂的设计灵感来自于 DNA 核碱基发展精确和明确的氢键的能力。我们已经表明,这种现象可用于创建一种有用的有机催化剂,该催化剂显示出类似于常见有机底物的识别模式。基于鸟嘌呤结构的选定双功能催化剂已被证明可催化 1,3-二羰基化合物与各种硝基烯烃的共轭加成,从而以良好的产率和对映选择性提供产品。
One stone four birds: A single chiral primaryamine was found to catalyze unprecedented asymmetric retro‐aldol and transfer‐aldol reactions, leading to four different chiral aldol adducts from one common chiral source with up to 99:1 d.r. and 99 % ee (see scheme).
Structural optimization of thiourea-based bifunctional organocatalysts for the highly enantioselective dynamic kinetic resolution of azlactones
作者:Albrecht Berkessel、Santanu Mukherjee、Thomas N. Müller、Felix Cleemann、Katrin Roland、Marc Brandenburg、Jörg-M. Neudörfl、Johann Lex
DOI:10.1039/b607574f
日期:——
describes the synthesis of a library of structurally diverse bifunctionalorganocatalysts bearing both a quasi-Lewis acidic (thio)urea moiety and a Bronsted basic tertiary amine group. Sequential modification of the modular catalyst structure and subsequent screening of the compounds in the alcoholytic dynamickineticresolution (DKR) of azlactones revealed valuable structure-activity relationships. In particular
Highly enantioselective one-pot sequential synthesis of valerolactones and pyrazolones bearing all-carbon quaternary stereocentres
作者:Yan-Li Xu、Zhou-Zhou Qin、Yu-Xia Wang、Peng-Fei Zhao、Hong-Feng Li、Zhi-Hong Du、Chao-Shan Da
DOI:10.1039/d0ob02489a
日期:——
Highly enantiopure and bioactive δ-valerolactones and pyrazolones, bearing α-all-carbon quaternary stereocentres, were successfully and sequentially prepared via a one-pot procedure starting from readily available, inexpensive materials, catalysed by a new chiral squaramide under mild reaction conditions. An organocatalytic Michael reaction afforded the valerolactones, while a one-pot Michael-hydr
regio- and diastereoselectivity and enantioselectivity under ambient temperature. Significantly, the reactions accommodate the synthetically important but challenging substrates, such as linear aliphaticketones, with high regioselectivity and unprecedented syn diastereoselectivity. These results are in sharp contrast with the secondary amine mediated similar reactions wherein anti diastereoselectivity
New bifunctional organocatalysts based on (R,R)-cyclohexane-1,2-diamine for the asymmetric addition of nucleophiles to aldehydes
作者:V. I. Maleev、Z. T. Gugkaeva、A. T. Tsaloev、M. A. Moskalenko、V. N. Khrustalev
DOI:10.1007/s11172-012-0008-7
日期:2012.1
The amide and sulfamide derivatives of (1R,2R)-N,N-diethylcyclohexane-1,2-diamine can serve as organocatalysts for addition of Me3SiCN and Et2Zn to aldehydes.