A green and efficient procedure for the preparation of valuable 2,3-dihydrofurans and benzoxazines has been achieved through halocyclization of olefinic 1,3-dicarbonyls or olefinic amides. This protocol could be conducted under catalyst-, base-, and oxidant-free conditions in aqueous media open to the air at room temperature with good to excellent yields. Notably, the practicality of this method is further highlighted by gram-scale reactions in good yields.

中文翻译：

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室温下在空气中开放的水性介质中的1,3-二羰基烯烃和酰胺的卤代化

通过烯烃1，3-二羰基或烯烃酰胺的卤代环化，已经实现了绿色高效的制备有价值的2，3-二氢呋喃和苯并恶嗪的方法。该规程可以在无催化剂，无碱和无氧化剂的条件下，在室温下对空气开放的水性介质中以良好至极好的收率进行。值得注意的是，该方法的实用性通过克规模的反应以高收率进一步突出。