An unprecedented N-stereogenic center playing an impressive role in the iridium/Rong-Phos-catalyzed enantio-divergent asymmetric hydrogenation was observed. Rong-Phos is easily prepared from readily available starting materials, which selectively form two diastereoisomeric Ir-complexes with fixed N-chirality depending on the coordination conditions.
An enantiodivergent strategy for the synthesis of trans-3,4-disubstituted succinimides is reported. The key step is a highly trans-stereoselective SmI2-induced Reformatsky-type reaction of 4-substituted-O-benzoylated malimides with carbonyl compounds. Double chirality transmissions were performed with good to excellent diastereoselectivities.
Iridium-Catalyzed Asymmetric Hydrogenation of α-Alkylidene Succinimides
作者:Yuanyuan Liu、Wanbin Zhang
DOI:10.1002/anie.201209126
日期:2013.2.18
Not to be out PhOXed! The title reaction provides a new approach to chiral succinimide derivatives with excellent yields and ee values by using a low catalyst loading (0.05 mol %) and mild reaction conditions. Chiral 3‐benzyl pyrrolidines and 1‐hydroxypyrrolidine‐2,5‐diones, important structural motifs in natural products and pharmaceuticals, could be readily prepared. BARF−=tetrakis[3,5‐bis(trifl