Catalyst-free annulations of 2-(4H-benzo[d][1,3]oxazin-4-yl)acrylates have been successfully achieved under mild conditions. Specifically, the reaction of 2-(4H-benzo[d][1,3]oxazin-4-yl)acrylates with sulfur ylides furnished various 1,2-dihydroquinolines in generally high yields. Furthermore, [3+2]-annulations of 2-(4H-benzo[d][1,3]oxazin-4-yl)acrylates with α,β-unsaturated imines afforded a broad scope of polysubstituted 2,3-dihydropyrroles with high efficiency.

中文翻译：

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2-(4H-苯并[d][1,3]恶嗪-4-基)丙烯酸酯的无催化剂反应：合成1,2-二氢喹啉和2,3-二氢吡咯


在温和条件下成功实现了 2-(4H-苯并[d][1,3]恶嗪-4-基)丙烯酸酯的无催化剂成环。具体而言，2-(4H-苯并[d][1,3]恶嗪-4-基)丙烯酸酯与硫叶立德的反应通常以高收率提供各种1,2-二氢喹啉。此外，2-(4H-苯并[d][1,3]恶嗪-4-基)丙烯酸酯与α,β-不饱和亚胺的[3+2]-环化提供了广泛的多取代2,3-二氢吡咯高效率。