作者:Daniel Polyak、Ngan Phung、Jian Liu、Robert Barrows、Thomas J. Emge、Spencer Knapp
DOI:10.1016/j.tetlet.2017.08.070
日期:2017.10
Homophthalic anhydride (HPA) typically reacts rapidly with benzalimines to afford the formal [4+2] adduct, a 1,2,3,4-tetrahydroisoquinolin-1-one-4-carboxylic acid. The stereochemical outcome of this reaction is consistent with an open transition state comprising an iminium species and enolized HPA, leading to a short-lived amino-anhydride intermediate. In the case of N-tert-butylbenzalimine, this Mannich-type
高邻苯二甲酸酐(HPA)通常与苯扎利明快速反应,得到正式的[4 + 2]加合物,即1,2,3,4-四氢异喹啉-1-一-4-羧酸。该反应的立体化学结果与包含亚胺基物种和烯醇化的HPA的开放过渡态相一致,从而导致氨基酸酐中间体的寿命短。在的情况下ñ -叔-butylbenzalimine,这曼尼希型中间,这通常环化在低温下向的单一异构体增量内酰胺,通过碱处理截获,得到的β内酰胺产品。涉及以烯酮形成随后闭环为特征的途径。