Non-Precious Metals Catalyze Formal [4 + 2] Cycloaddition Reactions of 1,2-Diazines and Siloxyalkynes under Ambient Conditions
نویسندگان
چکیده
Copper(I) and nickel(0) complexes catalyze the formal [4 + 2] cycloaddition reactions of 1,2-diazines and siloxyalkynes, a reaction hitherto best catalyzed by silver salts. These catalysts based on earth abundant metals are not only competent, but the copper catalyst, in particular, promotes cycloadditions of pyrido[2,3-d]pyridazine and pyrido[3,4-d]pyridazine, enabling a new synthesis of quinoline and isoquinoline derivatives, as well as the formal [2 + 2] cycloaddition reaction of cyclohexenone with a siloxyalkyne.
منابع مشابه
INVERSE-ELECTRON-DEMAND DIELS-ALDER REACTIONS OF CONDENSED PYRIDAZINES, 5.1 1,4-BIS(TRIFLUOROMETHYL)- PYRIDAZINO[4,5-b]INDOLE AS AN AZADIENE
The pyridazino[4,5-b]indole (3), which is conveniently available from 3-methylthioindole and the tetrazine (2), undergoes thermally induced inverseelectron-demand Diels-Alder reactions with enamines to afford the cycloalkeneannelated carbazoles (7,8) or the 2-substituted carbazole (9), respectively. We have previously shown that 1,2-diazines annelated to a second π-electron-deficient aromatic r...
متن کاملAn approach for the synthesis of nakamuric acid.
The biosynthesis of dimeric pyrrole-imidazole alkaloids is likely mediated by enzyme-catalyzed reversible single-electron transfer (SET) cycloaddition. We now show that Ir(ppy)3 can promote SET-mediated formal [2+2] and [4+2] cycloaddition reactions of pyrrole-imidazole alkaloids-related substrates under photolytic conditions. This biomimetic approach is useful for the construction of the core ...
متن کاملMetal-free cyclotrimerization for the de novo synthesis of pyridines.
The de novo synthesis of pyridines from smaller molecules has attracted a lot of interest since pyridine is one of the most important heterocyclic structural motifs in numerous areas of organic chemistry. Many developed syntheses, such as the Kr hnke or the Hantzsch reaction, rely on condensation reactions of smaller molecules, but a number of synthetic approaches including cycloaddition reacti...
متن کاملGold(I)-catalyzed diastereo- and enantioselective 1,3-dipolar cycloaddition and Mannich reactions of azlactones.
Azlactones participate in stereoselective reactions with electron-deficient alkenes and N-sulfonyl aldimines to give products of 1,3-dipolar cycloaddition and Mannich addition reactions, respectively. Both of these reactions proceed with good to excellent diastereo- and enantioselectivity using a single class of gold catalysts, namely C(2)-symmetric bis(phosphinegold(I) carboxylate) complexes. ...
متن کاملSynthesis and Molecular Docking studies of Some Tetrahydroimidazo[1,2-a] pyridine Derivatives as Potent α-Glucosidase Inhibitors
KAl(SO4)2.12H2O is found to efficiently and heterogeneously catalyze the one-pot three-component reaction of 2-(nitromethylene)imidazolidine, malononitrile and aldehydes under mild conditions to afford the corresponding tetrahydroimidazo[1,2-a]pyridine in good yields and short reaction times. Docking study of some compounds in the active site of α-glucosidase demonstrated that these...
متن کامل