The ketene silyl acetal derived from ethyl 2‐benzyltetrahydroisoquinoline‐1‐carboxylate undergoes a rapid oxidation reaction with N‐bromosuccinimide to form 3,4‐dihydroisoquinolinium ion, which reacts with Grignard reagents to give 1,1‐disubstituted tetrahydroisoquinolines in good yields.

中文翻译：

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3,4-二氢异喹啉鎓离子形成的有效方法，可轻松引入亲核试剂

源自2-苄基四氢异喹啉-1-羧酸乙酯的乙烯酮甲硅烷基缩醛与N-溴琥珀酰亚胺发生快速氧化反应，形成3,4-二氢异喹啉鎓离子，该离子与Grignard试剂反应生成1,1-二取代的四氢异喹啉，收率良好。