Au-catalyzed synthesis of 5,6-dihydro-8H-indolizin-7-ones from readily available N-(pent-2-en-4-ynyl)-beta-lactams is developed. In this reaction, a 5-exo-dig cyclization of the beta-lactam nitrogen to the Au-activated C-C triple bond is followed by heterolytic fragmentation of the amide bond, forming a highly nucleophilic acyl cation. An expedient formal synthesis of indolizidine 167B was easily achieved using this new method.

中文翻译：

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Au催化从N-（戊-2-烯-4-炔基）-β-内酰胺合成5,6-二氢-8H-吲哚嗪-7-酮。

从容易获得的N-（戊-2-烯-4-炔基）-β-内酰胺的Au催化合成5，6-二氢-8H-吲哚嗪-7-酮。在该反应中，将β-内酰胺氮5-Au-dig环化为Au活化的CC三键，然后酰胺键进行杂合裂解，形成高度亲核的酰基阳离子。使用这种新方法很容易实现吲哚并立定167B的简便形式合成。