An efficient synthesis of propargylamines via C–H activation catalyzed by copper(i) in ionic liquids

Abstract

A readily available copper(I) catalyst, in an ionic liquid, can effect three-component coupling of aldehydes, amines and alkynes to generate propargylamines in high yields.

Synthesis of 3‐Substituted Furans by Hydroformylation

“…This factor is important for the reaction of aryl halides containing electron-withdrawing substituents in which case the rate of coupling is faster than the reoxidation of the Pd(0) complex. [13] Aryl iodides containing electron-withdrawing substituents more readily underwent oxidative addition giving higher yields (entries 1, and 2). With electron-rich substrates, the corresponding coupling reactions proceeded more slowly (entries 5 -9).…”

“…The autoclave was depressurized, the reaction mixture filtered through Florisil, and the solvent was removed by rotary evaporation. The resulting yellow residue was directly subjected to 1 H and 13 C NMR spectroscopy. The crude was purified by silica gel chromatography or thin layer chromatography using pentane as the eluent to afford the pure product 2.…”

Palladium‐Katalysatorsysteme für die Synthese von konjugierten Eninen durch Sonogashira‐Kupplungen und verwandte Alkinylierungen

“…B. Benzyltriethylammoniumchlorid) zu den früh untersuchten Varianten gehören, [117] Park und Alper nutzten das phosphanfreie PalladiumBisimidazol-System 21 zur kupferfreien Kupplung von Aryliodiden (Schema 51). [120] Die Kupplung mit dem terminalen Alkin Phenylacetylen ergab mittlere bis ausgezeichnete Ausbeuten (32-98 %, je nach Substitution des Aryliodids), während die Kupplung anderer Alkine mit 4-Iodacetophenon etwas schwieriger war (28-58 % Ausbeute an isoliertem Produkt).…”

“…[120] Srinivasan et al führten eine Heck-Alkinylierung mit Aryliodiden unter Ultraschallbehandlung in dem flüssigen Imidazoliumsalz [BBim][BF 4 ] (1,3-Di-n-butylimidazoliumtetrafluoroborat) bei 30 8C durch; [121] die Autoren geben in situ gebildete Palladium(0)-Nanopartikel als möglichen Katalysator an (siehe Abschnitt 3.1.3). Dagegen berichten García et al über geringe Aktivitäten bei den Kupplungen von aktivierten Aryliodiden und -bromiden in Gegenwart von Palladiumschwarz, einem Palladiumcarbenkomplex oder einem Carbapalladacyclus bei 120 8C in verschiedenen flüs-sigen Imidazoliumsalzen (0-57 % Ausbeute).…”

Ionic liquids: a versatile medium for palladium-catalyzed reactions

“…[151][152][153][154] Cl] catalyzes this reaction efficiently without copper salts or bulky phosphine ligands in IL, and catalyst was recycled many times without any loss of catalytic activity. 152 Crosscoupling and carbonylative coupling of terminal alkynes with aryl iodides catalyzed by PdCl 2 (P(OPh) 3 ) 2 in the presence of Et 3 N in toluene results in the formation of the product in good yield. Same reaction was also performed 153 6 ] (mokt = 1-methyl-3-octyl imidazolium cation), catalyst was recycled and used in four consecutive catalytic cycles without loss of catalytic activity.…”