An In(OTf)₃-catalyzed intermolecular [3 + 2] annulation for the synthesis of 2,3-dihydro-1H-benzo[e]indoles and 2,3-dihydrobenzofurans from readily available substrates has been achieved. This approach takes advantage of oxetane and para-quinone methide as important functional units in the key intermediate. β-Naphthylamines and phenols have been demonstrated as excellent reaction partners.

中文翻译：

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In（OTf）₃催化[3 + 2]合成2,3-二氢-1 H-苯并[ e ]吲哚和2,3-二氢苯并呋喃

已实现了一种由In（OTf）₃催化的分子间[3 + 2]环合反应，用于从易于获得的底物中合成2,3-二氢-1 H-苯并[ e ]吲哚和2,3-二氢苯并呋喃。该方法利用氧杂环丁烷和对苯二甲酰甲烷作为关键中间体中的重要功能单元。β-萘胺和苯酚已被证明是极好的反应伴侣。