77396-68-0Relevant articles and documents
"Click" Chemistry: Application of Copper Metal in Cu-Catalyzed Azomethine Imine-Alkyne Cycloadditions
Pu?avec Kirar, Eva,Gro?elj, Uro?,Mirri, Giorgio,Po?gan, Franc,Strle, Gregor,?tefane, Bogdan,Jovanovski, Vasko,Svete, Jurij
, p. 5988 - 5997 (2016)
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 CuI-acetylide formed from Cu0 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.
Regioselective 1,3-dipolar cycloadditions of (1Z)-1-(arylmethylidene)-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ide azomethine imines to acetylenic dipolarophiles
Turk, Cvetka,Svete, Jurij,Stanovnik, Branko,Golic, Ljubo,Golic-Grdadolnik, Simona,Golobic, Amalija,Selic, Lovro
, p. 146 - 156 (2007/10/03)
The 5,5-dimethylpyrazolidin-3-one (4), prepared from ethyl 3-methylbut-2-enoate (3) and hydrazine hydrate, was treated with various substituted benzaldehydes 5a-i to give the corresponding (1Z)-1-(arylmethylidene)-5,5-dimethyl-3-oxopyrazolidin-1-ium-2-ide azomethine imines 6a-i. The 1,3-dipolar cycloaddition reactions of azomethine imines 6a-h with dimethyl acetylenedicarboxylate (=dimethyl but-2-ynedioate; 7) afforded the corresponding dimethyl pyrazolo[1,2-a]pyrazoledicarboxylates 8a-h, while by cycloaddition of 6 with methyl propiolate (= methyl prop-2-ynoate: 9), regioisomeric methyl pyrazolo[1,2-a]pyrazolemonocarboxylates 10 and 11 were obtained. The regioselectivity of cycloadditions of azomethine imines 6a- i with methyl propiolate (9) was influenced by the substituents on the aryl residue. Thus, azomethine imines 6a-e derived from benzaldehydes 5a-e with a single substituent or without a substituent at the orthopositions in the aryl residue, led to mixtures of regioisomers 10a-e and 11a-e. Azomethine imines 6f-i derived from 2,6-disubstituted benzaldehydes 5f-i gave single regioisomers 10f-i.
