Development of a Cysteine-Catalyzed Enantioselective Rauhut−Currier Reaction
摘要:
Herein, we report a full account of the development of an enantioselective Rauhut-Currier process that affords products in high yields and enantioselectivities using a cysteine-based catalyst. While traditional Morita-Baylis-Hillman catalysts were found to be essentially ineffective, various derivatives of protected cysteine were found to exhibit extraordinary reactivity and enantiotopic control. Extensive screening of reaction conditions led us to discover the enhanced effects of water as an additive and the chelating power of potassium in achieving higher enantiomer ratios. Mechanistic experiments also provided insight on the potential mechanism of the reaction in addition to possible transition states that provide the absolute stereochemistry formed in the observed products. Also included is a brief survey of the reaction scope involving different ring sizes as well as functionalized substrates.
Metal‐Organic Layers Catalyze Photoreactions without Pore Size and Diffusion Limitations
作者:Ruoyu Xu、Tasha Drake、Guangxu Lan、Wenbin Lin
DOI:10.1002/chem.201803635
日期:2018.10.22
limitation and slow diffusion, which are detrimental for photoreactions. Metal‐organic layers (MOLs) have unique ultrathin 2D monolayer structures and overcome pore size and diffusion limitations. Here, the synthesis of photoactive Zr‐RuBPY MOL based on Zr‐oxo clusters and [Ru(bpy)3]2+‐containing linkers is reported as well as its application in photocatalytic [2+2] cyclizations of enones and Meerwein
Thermodynamic epimeric equilibration and crystallisation-induced dynamic resolution of lobelanine, norlobelanine and related analogues
作者:Z. Amara、G. Bernadat、P.-E. Venot、P. Retailleau、C. Troufflard、E. Drège、F. Le Bideau、D. Joseph
DOI:10.1039/c4ob01787k
日期:——
β-aminoketone subunit, lobelanine is prone to self-catalyze mutarotation in solution. Through the synthesis of original lobelanine analogues, we studied the influence of (i) the size of the central heterocycle, (ii) the bulkiness of the nitrogen protecting group, and (iii) the phenacyl arm substituent on the thermodynamic equilibrium and its displacement by crystallisation-induced dynamic resolution
Carbon Nucleophile-Initiated Rauhut–Currier Reaction: An Atom-Economical Synthesis of Highly Functionalized Carbocycles
作者:Nicolas Gigant、Emmanuelle Drège、Delphine Joseph
DOI:10.1021/acs.joc.3c00513
日期:2023.8.18
A Rauhut–Currier reaction cascade is achieved in the presence of carbon nucleophiles under mild conditions. This original atom-economical transformation enables an efficient one-pot synthesis of densely substituted carbocycles from readily accessible substrates. The key promoter role of the cesium cation in the cascade process was demonstrated.