Efficient asymmetric selenocyclizations of alkenyl oximes into cyclic nitrones and 1,2-oxazines promoted by sulfur containing diselenides
作者:Marcello Tiecco、Lorenzo Testaferri、Luana Bagnoli、Valentina Purgatorio、Andrea Temperini、Francesca Marini、Claudio Santi
DOI:10.1016/s0957-4166(02)00013-7
日期:2001.12
were used in situ to promote the asymmetric selenocyclization of γ-alkenyl oximes and δ-phenyl-γ-alkenyl oximes. The course of these reactions and hence the structures of the cyclization products were dictated by the (E)- or (Z)-geometry of the starting oximes. The two types of cyclization products were either the cyclic nitrones or the 1,2-oxazines; in both cases the reactions proceeded with excellent
用溴处理二-2-[((1S)-1-(甲硫基)乙基]苯基二硒化物或二-2-甲氧基-6-[((1S ] -1-甲硫基)乙基]苯基二硒化物三氟甲磺酸银可提供相应的亲电子的硒化三氟甲磺酸酯,该三氟甲磺酸酯原位用于促进γ-烯基肟和δ-苯基-γ-烯基肟的不对称硒烯环化。这些反应的过程以及因此环化产物的结构由起始肟的(E)-或(Z)-几何形状决定。两种类型的环化产物是环状硝酮或1,2-恶嗪。在两种情况下,反应均以优异的收率,完全的区域选择性和良好的非对映选择性进行。