A chiral, ammonium ylide based access to tetrasubstituted 2,3-dihydrofurans starting from readily available benzylidene dicarbonyls and bromo acetophenones has been developed. The products are obtained in moderate to good yields with excellent diasteroselectivity and good to excellent enantioselectivity (up to 99:1 e.r.). The employed chiral amine can be recovered in near quantitative yield. The transformation can be run as a three-component one-pot reaction, generating the ammonium salt and ylide in situ. The scope of this reaction includes 17 new dihydrofurans with aromatic or heteroaromatic substituents.

中文翻译：

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叶立德铵对映选择性合成 2,3-二氢呋喃

已经开发了一种手性的、基于叶立德铵的方法，从容易获得的亚苄基二羰基化合物和溴苯乙酮开始获得四取代的 2,3-二氢呋喃。产品以中等至良好的收率获得，具有出色的非对映选择性和良好至出色的对映选择性（高达 99:1 er）。所使用的手性胺可以以接近定量的收率回收。该转化可以作为三组分一锅反应进行，原位生成铵盐和叶立德。该反应的范围包括 17 个带有芳香族或杂芳香族取代基的新二氢呋喃。