1,3-Dipolar cycloaddition of azomethine imines to ethynyl hetarenes: A synthetic route to 2,3-dihydropyrazolo[1,2- a ]pyrazol-1(5 H )-one based heterobiaryls
作者:Julia I. Nelina-Nemtseva、Anna V. Gulevskaya、Vitaliy V. Suslonov、Alexander D. Misharev
DOI:10.1016/j.tet.2018.01.046
日期:2018.3
π-Deficient ethynyl hetarenes were used as dipolarophiles in a 1,3-dipolar cycloaddition reaction with azomethine imines (2-arylidene-5-oxopyrazolidin-2-ium-1-ides). Both CuI-catalyzed and catalyst-free thermally induced reactions proceeded with high regioselectivity providing 6-hetaryl-5-aryl-2,3-dihydropyrazolo[1,2-a]pyrazol-1(5H)-ones in moderate to excellent yields. The ethynyl hetarenes (pyridines
在与偶氮甲亚胺(1,2-亚芳基-5-氧并吡唑并丁-2-盐-1-化物)进行的1,3-偶极环加成反应中,将π缺乏的乙炔基戊烯用作偶极亲和剂。CuI催化的和无催化剂的热诱导反应均以高区域选择性进行,从而以中等至优异的产率提供了6-杂芳基-5-芳基-2,3-二氢吡唑并[1,2- a ]吡唑-1(5 H)-一。 。乙炔基戊烯(吡啶,吡嗪,喹喔啉,蝶啶和嘧啶[4,5- c ]哒嗪)与邻甲基,邻氰基和邻甲基-炔基取代基适用于该反应。炔基戊烯与偶氮甲亚胺或其他1,3-偶极试剂的1,3-偶极环加成反应可以被视为杂二芳基化合物的另一种合成方法。