Enolate Ions as β-Activators of Ortho-Metalation: Direct Synthesis of 3-Aminoindenones
作者:Nadim E. Kayaleh、Ramesh C. Gupta、Francis Johnson
DOI:10.1021/jo991968k
日期:2000.7.1
condensation of benzoate esters with alkyl- or phenylacetonitriles lead to 3-aminoindenones in the presence of excess LDA. This new reaction is also applicable to pyridine carboxylic esters. All of the 3-aminoindenones and their aza analogues can be hydrolyzed by acid to give the corresponding 1,3-indandiones. The mechanism of the reaction falls into the directed-ortho-metalation class in which the initial
在过量LDA存在下,苯甲酸酯与烷基或苯基乙腈的克莱森缩合反应衍生的β-乙腈会生成3-氨基茚满。该新反应也适用于吡啶羧酸酯。所有的3-氨基茚满和它们的氮杂类似物都可以被酸水解,得到相应的1,3-茚满二酮。该反应的机理属于定向原位金属化类别,在该类别中,酮腈的初始烯醇盐离子将自金属化引导至邻位。然后,新的阴离子环化到腈基上以生成氨基茚满酮。令人惊讶的是,该系列中最简单的成员,苯甲酰基乙腈没有进行环化。机理同位素研究表明,该物质优先且直接在侧链上形成二价阴离子,