Max-Planck-Institut für Molekulare Physiologie, Abteilung Chemische Biologie, Otto-Hahn-Strasse 11, 44227, Dortmund, Germany.
Technische Universität Dortmund, Fakultät Chemie, Chemische Biologie, Chemische Biologie, Otto-Hahn-Strasse 4a, 44227, Dortmund, Germany.
Angew Chem Int Ed Engl. 2018 Oct 26;57(44):14493-14497. doi: 10.1002/anie.201712882. Epub 2018 Mar 1.
Spirotropanyl oxindole alkaloids like alstonisine and chitosenine show a wide range of bioactivites. We report the first enantioselective synthesis of the spirotropanyl oxindole scaffold by means of a bimetallic relay catalysis strategy. A new class of E-oximino α-diazo ketones was developed for the intramolecular generation of transient azomethine ylides catalyzed by an achiral Rh complex and a subsequent intermolecular 1,3-dipolar cycloaddition catalyzed by a chiral N,N'-dioxide Nd Lewis acid complex. The enantioselectively catalyzed transformation has broad scope and yields the desired spirotropanyl oxindole cycloadducts in high yields and with very high enantio- and diastereoselectivity.
螺旋托品烷氧吲哚类生物碱，如阿斯顿碱和奇托辛，具有广泛的生物活性。我们报告了首例通过双金属接力催化策略对螺旋托品烷氧吲哚骨架进行的对映选择性合成。我们开发了一类新的 E-肟基α-重氮酮，用于在非手性 Rh 配合物的催化下，通过分子内生成瞬态亚胺叶立德，并在随后的手性 N，N'-二氧化钕 Lewis 酸配合物的催化下进行分子间 1,3-偶极环加成反应。这种对映选择性催化转化具有广泛的适用范围，能够以高产率和非常高的对映选择性和非对映选择性得到所需的螺旋托品烷氧吲哚环加成产物。
