The synthesis of oxazolines using electrophilic cyclization of allylic amide is a simple and powerful method. However, cyclization involving arylsulfenylation requires harsh reaction conditions. We found that the reaction proceeds under mild heating conditions with the combination of a Bronsted acid and tetrabutylammonium chloride. This method enabled the synthesis of 5-[(arylsulfenyl)methyl]oxazoline derivatives under mild conditions and demonstrated high tolerance for various functional groups.

中文翻译：

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5-[(苯硫基)甲基]恶唑啉衍生物的改进合成方法：在温和条件下使用布朗斯台德酸和四丁基氯化铵亲电环化烯丙酰胺

使用烯丙酰胺的亲电环化合成恶唑啉是一种简单而有效的方法。然而，涉及芳基亚磺酰化的环化需要苛刻的反应条件。我们发现反应在温和加热条件下进行，同时使用布朗斯台德酸和四丁基氯化铵。该方法能够在温和的条件下合成 5-[(芳基硫基) 甲基] 恶唑啉衍生物，并显示出对各种官能团的高度耐受性。