title: Michael-type addition of azoles of broad-scale acidity to methyl acrylate.
abstract: An optimisation of Michael-type addition of azole derivatives of broad-scale acidity - ranging from 5.20 to 15.00 pK(a) units - namely 4-nitropyrazole, 3,5-dimethyl-4-nitropyrazole, 4(5)-nitroimidazole, 4,5-diphenylimidazole, 4,5-dicyanoimidazole, 2-methyl-4(5)-nitroimidazole, 5(4)-bromo-2-methyl-4(5)-nitroimidazole and 3-nitro-1,2,4-triazole to methyl acrylate as an acceptor was carried out. The optimisation process involved the use of an appropriate basic catalyst (DBU, DIPEA, NaOH, NaH, TEDA), a donor/base/acceptor ratio and the reaction temperature. The reactions were performed in DMF as solvent. Target Michael adducts were obtained in medium to excellent yields. Importantly, for imidazole and 1,2,4-triazole derivatives, no corresponding regioisomers were obtained.
authors: Silesian University of Technology, Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Krzywoustego 4, 44-100 Gliwice, Poland, Tel.: +48 32 237 1792.
authors: Sławomir
authors: S
authors: Boncel
authors: Kinga
authors: K
authors: Saletra
authors: Barbara
authors: B
authors: Hefczyc
authors: Krzysztof Z
authors: KZ
authors: Walczak