Affiliation:
1. Henan Key Laboratory of Chemical Biology and Organic Chemistry Key Laboratory of Applied Chemistry of HenanUniversities Green Catalysis Center and College of Chemistry Zhengzhou University Zhengzhou 450052 People's Republic of China
Abstract
AbstractHerein, we report a chemo‐ and regioselective Rh‐catalyzed redox C7‐spiroannulation reaction of N‐benzo[d]imidazole indolines with maleimides, resulting in a series of N‐benzo[d]imidazole indoline fused azaspirocycles in up to 92% yield. The synthetic utility is demonstrated by the synthesis of highly functionalized nitrogen‐containing spiropolycyclic skeletons. The annulation reaction could also be performed with maleic esters and acrylates. The products were purified by simple filtration. The Rh catalyst can be recycled, and the reaction could be performed at gram‐scale using 0.5 mol% of catalyst, which makes this protocol potentially applicable in industry. Moreover, the efficient post‐modification of pharmaceutical molecules demonstrates its practicability.