utilized as an efficient heterogeneous recyclable catalyst for Knoevenagel condensationbetween poorly reactive β-diketones and aldehydes under solvent-free conditions. This protocol also works well with more reactive β-ketoesters. The condensation is efficient, clean, and mild. The scope and generality of the Knoevenagel condensation were investigated. The procedure led only to the Knoevenagel product,
Reaction of Corey Ylide with α,β-Unsaturated Ketones: Tuning of Chemoselectivity toward Dihydrofuran Synthesis
作者:Alexey O. Chagarovsky、Ekaterina M. Budynina、Olga A. Ivanova、Elena V. Villemson、Victor B. Rybakov、Igor V. Trushkov、Mikhail Ya. Melnikov
DOI:10.1021/ol500877c
日期:2014.6.6
A straightforward, efficient, and reliable approach to synthetically valuable 2,3-dihydrofurans via a reaction between Corey ylide and α,β-unsaturated ketones has been developed. The use of simple and widely spread starting materials as well as mild reaction conditions and scalability provide a broad scope of 2,3-dihydrofurans.
Enantioselective Zinc-Mediated Conjugate Addition of Terminal Alkynes to Enones
作者:Gonzalo Blay、Luz Cardona、José R. Pedro、Amparo Sanz-Marco
DOI:10.1002/chem.201201765
日期:2012.10.8
Zinc for conjugate alkynylation: The enantioselectiveconjugateaddition of terminalalkynes to 2‐arylidene‐1,3‐diketones in the presence of diethylzinc and a catalytic amount of (R)‐VANOL has been developed. The reaction can be applied to different aromatic and heteroaromatic alkynes and enones, giving the expected products in good yield and with enantiomeric excesses up to 91 %. The products can
Aerobic Oxidative N-Heterocyclic Carbene-Catalyzed Formal [3+3] Cyclization for the Synthesis of Tetrasubstituted Benzene Derivatives
作者:Sara Bacaicoa、Ellymay Goossens、Henrik Sundén
DOI:10.1021/acs.orglett.2c03879
日期:2022.12.16
Herein, we present an accessible aerobic N-heterocyclic carbene (NHC)-catalyzed method that efficiently produces tetrasubstituted benzene rings in a single reaction. The method employs atmospheric oxygen (O2) as the terminal oxidant in a reaction that requires two oxidative steps. The aerobic oxidation is achieved by a selection of electron transfer mediators orchestrating a redox cascade, turning
在此,我们提出了一种可获得的好氧 N-杂环卡宾 (NHC) 催化方法,该方法可在单个反应中有效地产生四取代苯环。该方法在需要两个氧化步骤的反应中使用大气中的氧气 (O 2 ) 作为末端氧化剂。有氧氧化是通过选择协调氧化还原级联的电子转移介质实现的,将高能有氧氧化反应途径转变为有利的过程。
Bernasconi, Claude F.; Stronach, Michael W., Journal of the American Chemical Society, 1991, vol. 113, # 6, p. 2222 - 2227