Duality of Donor-Acceptor Cyclopropane Reactivity as a Three-Carbon Component in Five-Membered Ring Construction: [3+2] Annulation Versus [3+2] Cycloaddition
作者:Yulia A. Volkova、Ekaterina M. Budynina、Alexey E. Kaplun、Olga A. Ivanova、Alexey O. Chagarovskiy、Dmitriy A. Skvortsov、Victor B. Rybakov、Igor V. Trushkov、Mikhail Ya. Melnikov
DOI:10.1002/chem.201300731
日期:2013.5.17
Quo vadis? The Lewis acid catalyzed reaction of (hetero)aryl‐derived donor–acceptorcyclopropanes with alkenes can be selectively directed along a [3+2] annulation pathway (see scheme). This new process provides convenient and efficient access to indanes and other cyclopentannulated (hetero)arenes, among which polyoxygenated 1‐arylindanes exhibit significant cytotoxicity against several cancer cell
Friedel-Crafts alkylation of benzo[b]furan with activated cyclopropanes catalyzed by a calcium(II) complex
作者:T. Parker Maloney、Kristen L. Murphy、Tafon L. Mainsah、Kristine A. Nolin
DOI:10.1016/j.tetlet.2017.10.064
日期:2018.1
The synthesis of γ-benzo[b]furanyl malonates was achieved through the addition of benzo[b]furan to activated cyclopropanes. These Friedel-Crafts reactions were catalyzed by calcium bis(trifluoromethanesulfonimide), Ca(NTf2)2 with tetrabutylammonium hexafluorophosphine as a co-catalyst. The additions proceeded with complete regioselectivity and in good to excellent yield. Optimization of the reaction
γ-苯并[ b ]呋喃基丙二酸酯的合成是通过将苯并[ b ]呋喃添加到活化的环丙烷中来实现的。用双(三氟甲磺酰亚胺)钙,Ca(NTf 2)2和四丁基铵六氟膦作为助催化剂催化这些Friedel-Crafts反应。添加以完全的区域选择性进行并且以良好至优异的产率进行。报道了反应条件的优化和关于在环丙烷上取代的方法范围的研究。
Tandem Cyclopropane Ring-Opening/Conia-ene Reactions of 2-Alkynyl Indoles: A [3 + 3] Annulative Route to Tetrahydrocarbazoles
作者:Huck K. Grover、Terry P. Lebold、Michael A. Kerr
DOI:10.1021/ol102627e
日期:2011.1.21
A Zn(NTf2)2catalyzed tandem reaction consisting of a nucelophilic ringopening of 1,1-cyclopropanediesters by 2-alkynyl indoles followed by a Conia-ene ring closure results in the efficient one-step synthesis of tetrahydrocarbazoles. The adducts may be further elaborated to carbazoles.
Synthesis of Tetrahydropyrans from Propargyl Alcohols and 1,1-Cyclopropanediesters: A One-Pot Ring-Opening/Conia-ene Protocol
作者:Andrew B. Leduc、Terry P. Lebold、Michael A. Kerr
DOI:10.1021/jo9019122
日期:2009.11.6
Lewis acid catalyzed ring opening of 1,1-cyclopropanediesters by the hydroxyl group of a propargylalcohol sets up a subsequent Conia-ene cyclization to afford substituted tetrahydropyrans in a one-pot, high-yielding procedure.
Regioselective Hydrogenolysis of Donor–Acceptor Cyclopropanes with Zn-AcOH Reductive System
作者:Konstantin L. Ivanov、Elena V. Villemson、Gennadij V. Latyshev、Stanislav I. Bezzubov、Alexander G. Majouga、Mikhail Ya. Melnikov、Ekaterina M. Budynina
DOI:10.1021/acs.joc.7b01549
日期:2017.9.15
convenient low-cost method for regioselective ring-opening of donor–acceptor cyclopropanes with the Zn-AcOH reductive system was developed. The general character of the method was displayed via efficient reduction of a representative series of 2-(het)arylcyclopropane-1,1-diesters as well as donor–acceptor cyclopropanes with other types of electron-withdrawing activating groups. This method opens a rapid