Asymmetric Synthesis of Trifluoromethylphenyl Cyclopropanes Catalyzed by Chiral Metalloporphyrins
作者:Gérard Simonneaux、Paul Le Maux、Sandrine Juillard
DOI:10.1055/s-2006-926451
日期:2006.5
The asymmetric addition of 2,2,2-trifluorodiazoethane to styrene derivatives to give optically active trifluoromethylphenyl cyclopropanes (ee values up to 69%) was carried out by using chiral iron and ruthenium porphyrins as homogeneous and heterogeneous catalysts.
Iron(III)-based metalloradical catalysis for asymmetric cyclopropanation via a stepwise radical mechanism
作者:Wan-Chen Cindy Lee、Duo-Sheng Wang、Yiling Zhu、X. Peter Zhang
DOI:10.1038/s41557-023-01317-8
日期:2023.11
initial application for asymmetric radical transformations. Specifically, we report that five-coordinate iron(III) complexes of porphyrins with an axial ligand, which represent another family of stable 15e-metalloradicals with a d5 configuration, are potent metalloradical catalysts for olefin cyclopropanation with different classes of diazocompounds via a stepwise radical mechanism. This work lays a foundation
Synthesis of Ring-Fluorinated Thiophene Derivatives Based on Single C–F Bond Activation of CF<sub>3</sub>-Cyclopropanes: Sulfanylation and 5-<i>endo</i>-<i>trig</i> Cyclization
作者:Kohei Fuchibe、Tatsuki Fushihara、Junji Ichikawa
DOI:10.1021/acs.orglett.0c00385
日期:2020.3.20
The treatment of CF3-bearing cyclopropanes with Et2AlCl generated stabilized difluorocarbocations, which underwent a nucleophilic addition of thiocarboxylic acids or thiols. The sulfur functionality was introduced at the position δ to the fluorine substituents in a regioselective manner (single activation of CF3-cyclopropanes). The formed 1,1-difluoro-1-alkenes underwent successive deesterification/5-endo-trig
Enantioselective Cobalt-Catalyzed Preparation of Trifluoromethyl-Substituted Cyclopropanes
作者:Bill Morandi、Brian Mariampillai、Erick M. Carreira
DOI:10.1002/anie.201004269
日期:2011.2.1
Easy access on water: A cobalt‐catalyzed asymmetric preparation of trifluoromethylcyclopropanes has been developed that yields high enantioselectivities with a broad range of styrene substrates (see scheme). The reaction presents a new access to enantioenriched CF3‐containing building blocks.