Vogl Lukas S, Mayer Peter, Robiette Raphaël, Waser Mario
Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040, Linz, Austria.
Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377, München, Germany.
Angew Chem Int Ed Engl. 2024 Jan 8;63(2):e202315345. doi: 10.1002/anie.202315345. Epub 2023 Dec 11.
Allenoates are versatile building blocks which are primarily activated and controlled using chiral tert. phosphine and tert. amine Lewis bases. We herein report the first example of allenoate activation by using chiral isochalcogenoureas (IChU) for formal (4+2) cycloaddition reactions. Compared to established phosphine and amine catalysis, the use of these easily available Lewis bases enables new stereoselective reaction pathways proceeding with high enantioselectivities, diastereoselectivities, and in good yields. In addition, the factors governing enantioselectivity and the origin of the observed differences compared to other commonly used Lewis bases are explained.
联烯酸酯是多功能的结构单元，主要通过手性叔膦和叔胺路易斯碱进行活化和控制。我们在此报告了首例使用手性异硫脲（IChU）活化联烯酸酯用于形式上的（4+2）环加成反应。与已有的膦催化和胺催化相比，使用这些易于获得的路易斯碱能够实现新的立体选择性反应途径，具有高对映选择性、非对映选择性且产率良好。此外，还解释了控制对映选择性的因素以及与其他常用路易斯碱相比所观察到差异的来源。
