Regioselective anionic [3+2] cyclizations of isoxazole, pyrazole and 1,2,4-triazole dinucleophiles - Efficient synthesis of 2,4-dihydroimidazo-[4,5-b]quinoxalines, 3H-imidazo[1,2-b]pyrazoles and 5H-imidazo[2,1-c][1,2,4]triazoles
Authors list: Langer, P; Wuckelt, J; Döring, M; Schreiner, PR; Görls, H
Abstract: Regioselective cyclization reactions between oxaldiimidoyl dichlorides and 3-aminopyrazole and 3-amino-1,2,4-triazole provide convenient access to biologically relevant 3H-imidazo[1,2-b]pyrazoles and a 5H-imidazo[2,1-c][1,2,4]triazole. In contrast, treatment of 3-aminoisoxazoles with diimidoyl dichlorides results in a new and efficient anionic domino process for the synthesis of biologically relevant 2,4-dihydro-1H-imidazo[4,5-b]quinoxalines. All cyclizations proceed with high regioselectivities, which are explained with the aid of semiempirical computations.
Harvard Citation style: Langer, P., Wuckelt, J., Döring, M., Schreiner, P. and Görls, H. (2001) Regioselective anionic [3+2] cyclizations of isoxazole, pyrazole and 1,2,4-triazole dinucleophiles - Efficient synthesis of 2,4-dihydroimidazo-[4,5-b]quinoxalines, 3H-imidazo[1,2-b]pyrazoles and 5H-imidazo[2,1-c][1,2,4]triazoles, European Journal of Organic Chemistry, 2001(12), pp. 2257-2263. https://doi.org/10.1002/1099-0690(200106)2001:12<2257::AID-EJOC2257>3.0.CO;2-Z
APA Citation style: Langer, P., Wuckelt, J., Döring, M., Schreiner, P., & Görls, H. (2001). Regioselective anionic [3+2] cyclizations of isoxazole, pyrazole and 1,2,4-triazole dinucleophiles - Efficient synthesis of 2,4-dihydroimidazo-[4,5-b]quinoxalines, 3H-imidazo[1,2-b]pyrazoles and 5H-imidazo[2,1-c][1,2,4]triazoles. European Journal of Organic Chemistry. 2001(12), 2257-2263. https://doi.org/10.1002/1099-0690(200106)2001:12<2257::AID-EJOC2257>3.0.CO;2-Z
