40735-09-9Relevant articles and documents
SOME NEW TRANSFORMATIONS OF CYCLOPROPYLACETYLENE CATALYZED BY RHODIUM, PALLADIUM, AND COBALT COMPLEXES
Dzhemilev, U. M.,Khusnutdinov, R. I.,Shchadneva, N. A.,Nefedov, O. M.,Tolstikov, G. A.
, p. 2171 - 2174 (1989)
The linear and cyclic dimerization and trimerization of cyclopropylacetylene were carried out by the action of rhodium, palladium, and cobalt catalysts to give 2,4-dicyclopropyl-1-buten-3-yne, 1,3,6-tricyclopropylfulvene, and 1,3,5- and 1,2,4-tricycloprop
Iron-catalyzed trimerization of terminal alkynes enabled by pyrimidinediimine ligands: A regioselective method for the synthesis of 1,3,5-substituted arenes
Doll, Julianna S.,Eichelmann, Robert,Hertwig, Leif E.,Bender, Thilo,Kohler, Vincenz J.,Bill, Eckhard,Wadepohl, Hubert,Ro?ca, Drago?-Adrian
, p. 5593 - 5600 (2021/05/31)
The development of pyrimidine-based analogues of the well-known pyridinediimine (PDI) iron complexes enables access to a functional-group-tolerant methodology for the catalytic trimerization of terminal aliphatic alkynes. Remarkably, in contrast to established alkyne trimerization protocols, the 1,3,5-substituted arenes are the main reaction products. Preliminary mechanistic investigations suggest that the enhanced π-acidity of the pyrimidine ring, combined with the hemilability of the imine groups coordinated to the iron center, facilitates this transformation. The entry point in the catalytic cycle is an isolable iron dinitrogen complex. The catalytic reaction proceeds via a 1,3-substituted metallacycle, which explains the observed 1,3,5-regioselectivity. Such a metallacycle could be isolated and represents a rare 1,3-substituted ferracycle obtained through alkyne cycloaddition.
Combined Photoredox and Iron Catalysis for the Cyclotrimerization of Alkynes
Chakraborty, Uttam,Jacobi von Wangelin, Axel,Neumeier, Michael,Perez-Ruiz, Raul,Schaarschmidt, Dieter,de la Pena O'Shea, Victor
supporting information, p. 13473 - 13478 (2020/06/02)
Successful combinations of visible-light photocatalysis with metal catalysis have recently enabled the development of hitherto unknown chemical reactions. Dual mechanisms from merging metal-free photocatalysts and earth-abundant metal catalysts are still in their infancy. We report a photo-organo-iron-catalyzed cyclotrimerization of alkynes by photoredox activation of a ligand-free Fe catalyst. The reaction operates under very mild conditions (visible light, 20 °C, 1 h) with 1–2 mol percent loading of the three catalysts (dye, amine, FeCl2).
Iron-Catalyzed Cyclotrimerization of Terminal Alkynes by Dual Catalyst Activation in the Absence of Reductants
Brenna, Davide,Villa, Matteo,Gieshoff, Tim N.,Fischer, Fabian,Hapke, Marko,Jacobi von Wangelin, Axel
supporting information, p. 8451 - 8454 (2017/07/11)
Catalyzing C?C bond-forming reactions with earth-abundant metals under mild conditions is at the heart of sustainable synthesis. The cyclotrimerization of alkynes is a valuable atom-efficient reaction in organic synthesis that is enabled by several metal catalysts, including iron. This study reports an effective iron-catalyzed cyclotrimerization for the regioselective synthesis of 1,2,4-substituted arenes (1 mol % catalyst, toluene, 20 °C, 5 min). A dual activation mechanism (substrate deprotonation, reductive elimination) renders the simple FeII precatalyst highly active in the absence of any reductant.
Efficient and regioselective nickel-catalyzed [2 + 2 + 2] cyclotrimerization of ynoates and related alkynes
Rodrigo, Sanjeewa K.,Powell, Israel V.,Coleman, Michael G.,Krause, Jeanette A.,Guan, Hairong
supporting information, p. 7653 - 7657 (2013/11/06)
A nickel-based catalytic system has been developed for [2 + 2 + 2] cyclotrimerization of various alkynes, especially ynoates. This catalytic system enables facile construction of substituted aromatic compounds in excellent yields with high regioselectivity. The Royal Society of Chemistry 2013.
