Indian Institute of Technology Bombay, Mumbai 400 076, Maharashtra, India.
J Org Chem. 2023 Apr 7;88(7):4038-4051. doi: 10.1021/acs.joc.2c00816. Epub 2022 Jul 7.
The reactivity of the Hauser-Kraus (H-K) donor, 3-sulfonylphthalide, with various activated imines under basic conditions is demonstrated. The reaction of 3-sulfonylphthalide with Boc-protected aldimine provides a rapid access to 1,2-imine adducts and alkylidenephthalides depending upon the stoichiometry of the base. The alkylidenephthalides could be transformed to ketophthalides, a new class of phthalides, on acid hydrolysis, which upon reductive cyclization using Zn/AcOH afforded the natural product homalicine. On the contrary, the Boc-protected isatinimines undergo an efficient H-K annulation to provide -isoquinolinone-oxindoles in excellent yields. However, the corresponding conjugated ketimines afforded Michael adducts, which were converted to the corresponding alkylidenephthalides under TBAF conditions.
本文展示了豪泽-克劳斯（Hauser-Kraus）供体 3-磺酰基邻苯二甲酰亚胺在碱性条件下与各种活化亚胺的反应性。3-磺酰基邻苯二甲酰亚胺与 Boc 保护的醛亚胺反应，根据碱的化学计量，可快速得到 1,2-亚胺加合物和亚甲基邻苯二甲酰亚胺。亚甲基邻苯二甲酰亚胺可在酸水解下转化为酮邻苯二甲酰亚胺，这是一类新的邻苯二甲酰亚胺，用 Zn/AcOH 还原环化可得到天然产物 homalicine。相反，Boc 保护的靛红亚胺经历有效的 H-K 稠合，以优异的收率提供 -异喹啉酮-氧吲哚。然而，相应的共轭酮亚胺生成迈克尔加成物，在 TBAF 条件下，这些加成物可转化为相应的亚甲基邻苯二甲酰亚胺。
