In connection with studies on the direction of cyclization in the Fischer indolization of substituted diphenylhydrazones, the Fischer indolization of ethyl pyruvate 2-bis(2-methoxyphenyl)hydrazone (6) was carried out. The result showed that cyclization in Fischer indolization of diphenylhydrazone does not always proceed to the electron-richer nucleus, but depends on the conformation of the enehydrazine. Thus, the Fischer indolization should proceed via a [3, 3] sigmatropic route, with an electronic effect.
为了研究取代的二苯
肼在费歇尔
吲哚化过程中的环化方向,我们对
丙酮酸乙酯 2-双(2-
甲氧基苯基)腙(6)进行了费歇尔
吲哚化。结果表明,在
二苯甲酮的费歇尔
吲哚化过程中,环化并不总是向电子稠合核进行,而是取决于烯
肼的构象。因此,费歇尔
吲哚化应通过[3, 3]西格玛途径进行,并具有电子效应。