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
作者:Peter Langer、Jörg Wuckelt、Manfred Döring、Peter R. Schreiner、Helmar Görls
DOI:10.1002/1099-0690(200106)2001:12<2257::aid-ejoc2257>3.0.co;2-z
日期:2001.6
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
草酰二亚氨基二氯化物与3-氨基吡唑和3-氨基-1,2,4-三唑之间的区域选择性环化反应可方便地获得生物学上相关的3 H-咪唑并[1,2- b ]吡唑和5 H-咪唑并[2,1 - ç ] [1,2,4]三唑。相反,用二亚氨基二氯化物处理3-氨基异恶唑导致了一种新的有效的阴离子多米诺方法,用于合成生物学上相关的2,4-二氢-1 H-咪唑并[4,5- b ]喹喔啉。所有环化反应都具有较高的区域选择性,这在半经验计算的帮助下进行了解释。