Bifunctional Brønsted Base Catalyzed [3 + 3] Annulations of Indolin-2-imines and α,β-Unsaturated Imides: An Enantioselective Approach to α-Carbolinones
Lin Chen, Xiang Zhang, Ke-Jin Shi, Hai‐Jun Leng, Qing‐Zhu Li, Yu Liu, Jianghong Li, Jiang-Hong Li, Qiwei Wang, Jun‐Long Li, Jun‐Long Li
Abstract
Asymmetric construction of α-carbolinones with easily available starting materials has recently attracted considerable attention from the synthesis community, and the development of effective catalysis for this target is in great demand. Here, a bifunctional Brønsted base catalyzed asymmetric [3 + 3] cyclization of indolin-2-imines and α,β-unsaturated N-acylated succinimides was developed by using the strategy of noncovalent bonding catalysis. With this organocatalytic protocol, a variety of tetrahydro-α-carbolinones bearing different substituents were synthesized with up to 99% yield and up to 96:4 er.
Topics & Concepts
BifunctionalEnantioselective synthesisOrganocatalysisCatalysisChemistryBrønsted–Lowry acid–base theoryYield (engineering)Base (topology)Combinatorial chemistryOrganic chemistryMathematicsMaterials scienceMetallurgyMathematical analysisAsymmetric Synthesis and CatalysisAlkaloids: synthesis and pharmacologySynthesis of Indole Derivatives