A Bulky Chiral N‐Heterocyclic Carbene Nickel Catalyst Enables Enantioselective C−H Functionalizations of Indoles and Pyrroles. Issue 32 (3rd July 2019)

• Record Type: Journal Article
• Authors: Diesel, Johannes; Grosheva, Daria; Kodama, Shota; Cramer, Nicolai
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 32(2019)
• Page Start: 11044
• Page End: 11048
• Publication Date: 2019-07-03
• Subjects: asymmetric catalysis -- C−H activation -- chiral NHC ligands -- heterocycles -- nickel; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201904774
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: An enantioselective nickel(0)‐catalyzed C−H functionalization of indoles and pyrroles that does not require the typical Lewis basic directing groups is disclosed. The reaction provides access to valuable tetrahydropyridoindoles and tetrahydroindolizines in high yields and enantioselectivity under mild reaction conditions. The process is characterized by a clear endo ‐cyclization preference to yield the sought‐after six‐membered‐ring products. Key for the success of the activation and selectivity in the cyclization was the development of a novel chiral SIPr carbene ligand analogue with very bulky flanking groups. Abstract : The incredible bulk : An enantioselective directing‐group‐free Ni 0 ‐catalyzed C−H functionalization of indoles provides access to tetrahydropyridoindoles and tetrahydroindolizines in high yields and enantioselectivity under mild reaction conditions. The activation and selective cyclization are enabled by a novel chiral SIPr carbene ligand analogue with very bulky flanking groups.