Iminium-functionalized 1,2,3-triazoles by [3+2] cycloaddition reactions of internal acetylenic iminium triflates with organoazides
作者:Christian J. Tontsch、Holger Gerster、Gerhard Maas
DOI:10.1515/znb-2019-0079
日期:2019.8.27
triflates 1–6 react as dipolarophiles in thermal [3 + 2]-cycloadditions with sufficiently electron rich organoazides to form 1,4,5-trisubstituted 1,2,3-triazoles with iminium functionalization. The reactions require rather strong thermal activation, but can be accelerated by microwave irradiation. The regioselectivity of the cycloaddition at the internal acetylenic bond of 3-cyclopropylpropyne and 3-arylpropyne
摘要 丙炔亚胺三氟甲磺酸酯 1-6 作为偶极亲和体在热 [3 + 2]-环加成反应中与足够富电子的有机叠氮化物反应,形成具有亚胺功能化的 1,4,5-三取代 1,2,3-三唑。反应需要相当强的热活化,但可以通过微波辐射加速。3-环丙基丙炔和 3-芳基丙炔亚胺离子(分别为 1-3 和 4)的内部炔键的环加成的区域选择性非常高,但在亚胺离子的另一端存在空间要求高的取代基时会降低-取代的C,C三键。亚胺官能化的三唑很容易转化为中性化合物;本文报道了通过水解形成三唑基酮10和通过LiAlH 4 还原形成叔三唑基二甲基胺12。