"Click" Chemistry: Application of Copper Metal in Cu-Catalyzed Azomethine Imine-Alkyne Cycloadditions.
A series of 16 copper-catalyzed azomethine imine-alkyne cycloaddition (CuAIAC) reactions between four pyrazolidinone-1-azomethine imines and four terminal ynones gave the corresponding fluorescent cycloadducts as bimane analogues in very high yields. The applicability of CuAIAC was demonstrated by the fluorescent labeling of functionalized polystyrene and by using Cu-C and Cu-Fe as catalysts. Experimental evidence, kinetic measurements, and correlation between a clean catalyst surface and the reaction rate are in agreement with a homotopic catalytic system with catalytic Cu(I)-acetylide formed from Cu(0) by "in situ" oxidation. The availability of azomethine imines, mild reaction conditions, simple workup, and scalability make CuAIAC a viable supplement to the Cu-catalyzed azide-alkyne cycloaddition reaction in "click" chemistry.
Faculty of Chemistry and Chemical Technology, University of Ljubljana , Večna Pot 113, SI-1000 Ljubljana, Slovenia.
Eva
E
Pušavec Kirar
Faculty of Chemistry and Chemical Technology, University of Ljubljana , Večna Pot 113, SI-1000 Ljubljana, Slovenia.
Uroš
U
Grošelj
Faculty of Chemistry and Chemical Technology, University of Ljubljana , Večna Pot 113, SI-1000 Ljubljana, Slovenia.
Giorgio
G
Mirri
Faculty of Chemistry and Chemical Technology, University of Ljubljana , Večna Pot 113, SI-1000 Ljubljana, Slovenia.
Franc
F
Požgan
Faculty of Chemistry and Chemical Technology, University of Ljubljana , Večna Pot 113, SI-1000 Ljubljana, Slovenia.
Gregor
G
Strle
Faculty of Chemistry and Chemical Technology, University of Ljubljana , Večna Pot 113, SI-1000 Ljubljana, Slovenia.
Bogdan
B
Štefane
National Institute of Chemistry , Hajdrihova 19, SI-1000 Ljubljana, Slovenia.
Vasko
V
Jovanovski
Faculty of Chemistry and Chemical Technology, University of Ljubljana , Večna Pot 113, SI-1000 Ljubljana, Slovenia.
Jurij
J
Svete