Saint Petersburg State University , Saint Petersburg 199034 , Russian Federation.
J Org Chem. 2019 Feb 15;84(4):1693-1705. doi: 10.1021/acs.joc.8b02805. Epub 2018 Dec 24.
The previously reported ring-expansion strategy involving hydrolytically prone imidazoline rings was thought to include the formation of a hydrated imidazoline intermediate. In this work, we accessed the latter via the addition of a 2-aminoethyl side chain onto a lactam moiety. This led to an efficient three-atom ring expansion of diarene-fused [1.4]oxazepines and [1.4]thiazepines and led us to propose to term this common approach the hydrated imidazoline ring expansion (HIRE) reaction. The strategy was extended to the insertion of longer (containing up to five atoms) side chains, and thus, larger (11- to 12-membered) diarene-fused rings were obtained via the homo-HIRE and homo-HIRE reactions, respectively. This underscores the utility of the HIRE reaction for the preparation of medium-sized rings, an important class of chemical tools for interrogation of various biological targets.
先前报道的涉及水解倾向的咪唑啉环的环扩张策略被认为包括形成水合咪唑啉中间体。在这项工作中，我们通过在酰胺部分上添加 2-氨基乙基侧链来获得后者。这导致二芳基稠合 [1.4]恶嗪和 [1.4]噻嗪的高效三原子环扩张，并促使我们提出将这种常见方法称为水合咪唑啉环扩张 (HIRE) 反应。该策略扩展到插入更长的（含有多达五个原子）侧链，因此，通过同-HIRE 和同-HIRE 反应分别获得更大的（11 到 12 元）二芳基稠合环。这突显了 HIRE 反应在制备中等大小环中的实用性，这些环是用于研究各种生物靶标的重要一类化学工具。
