15 January 2024 | Shao-Jie Wang, Xia Wang, Xiaolan Xin, Shulei Zhang, Hui Yang, Ming Wah Wong & Shenci Lu
This article presents an efficient method for the diastereo- and atroposelective synthesis of N–N axially chiral pyrroles and indoles using oxidative NHC (N-heterocyclic carbene) catalyzed (3+3) cycloaddition. The method enables the simultaneous creation of contiguous axial and central chirality, leading to the synthesis of structurally diverse N–N axially chiral pyrroles and indoles with high enantioselectivity and moderate to good yields. The reaction mechanism and enantioselectivity were elucidated through DFT calculations. The study highlights the importance of N–N axial chirality in natural products, pharmaceuticals, and chiral ligands. The method offers a new approach for the synthesis of atropisomeric compounds, with potential applications in catalysis and drug delivery. The research demonstrates the ability to control multiple chiral elements (axial and central chirality) in a single operation, addressing challenges in the construction of contiguous axial and central chirality. The results show that the reaction is highly stereoselective, with excellent enantioselectivity and diastereoselectivity. The study also explores the configurational stability of the synthesized compounds and their potential applications in synthetic chemistry, including functionalization and transformations. The findings contribute to the development of new methods for the synthesis of chiral molecules, particularly N–N atropisomers, using NHC catalysis.This article presents an efficient method for the diastereo- and atroposelective synthesis of N–N axially chiral pyrroles and indoles using oxidative NHC (N-heterocyclic carbene) catalyzed (3+3) cycloaddition. The method enables the simultaneous creation of contiguous axial and central chirality, leading to the synthesis of structurally diverse N–N axially chiral pyrroles and indoles with high enantioselectivity and moderate to good yields. The reaction mechanism and enantioselectivity were elucidated through DFT calculations. The study highlights the importance of N–N axial chirality in natural products, pharmaceuticals, and chiral ligands. The method offers a new approach for the synthesis of atropisomeric compounds, with potential applications in catalysis and drug delivery. The research demonstrates the ability to control multiple chiral elements (axial and central chirality) in a single operation, addressing challenges in the construction of contiguous axial and central chirality. The results show that the reaction is highly stereoselective, with excellent enantioselectivity and diastereoselectivity. The study also explores the configurational stability of the synthesized compounds and their potential applications in synthetic chemistry, including functionalization and transformations. The findings contribute to the development of new methods for the synthesis of chiral molecules, particularly N–N atropisomers, using NHC catalysis.