Article
Chemistry, Inorganic & Nuclear
Lingyu Kong, Yajie Chou, Muriel Albalat, Marion Jean, Nicolas Vanthuyne, Stephane Humbel, Paola Nava, Herve Clavier
Summary: The concept of atropisomeric N-heterocyclic carbene (NHC)-metal complexes with C-2-symmetry was extended to palladium-based complexes. Through a comprehensive study of NHC precursors and screening of various NHC ligands, the formation of meso complexes was successfully circumvented. Eight atropisomeric NHC-palladium complexes were prepared and obtained with high enantiopurities through efficient chiral HPLC resolution. These complexes demonstrated good activity in the intramolecular alpha-arylation of amides, leading to the isolation of cyclic products with excellent enantioselectivities (up to 98% ee).
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Organic
Binghao Liu, Jing Qi, Yatong Wu, Jia-Hui Li, Yanting Li, Xiao-Yong Duan
Summary: In this work, an efficient strategy for the construction of dimeric spirocyclic bisindoline alkaloid derivatives was introduced using NHC-catalyzed enantioselective [3 + 2] annulation of enals with isoindigo. The reaction successfully constructs three contiguous stereogenic centers, including two congested all-carbon quaternary stereogenic centers, in a simple one-step operation.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Yunpeng Chu, Fang Hu, Peng Feng, Xin-Ping Hui
Summary: The first N-heterocyclic carbene-catalyzed enantioselective dearomatizing annulation of benzoxazoles with alpha,beta-unsaturated aldehydes has been achieved, resulting in moderate to good yields and moderate to excellent enantioselectivities.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Sayan Shee, Soumen Barik, Arghya Ghosh, Akkattu T. Biju
Summary: This study describes a method for the facile synthesis of functionalized dihydrocoumarins catalyzed by N-heterocyclic carbene (NHC), in which initially formed NHC-homoenolates undergo a specific reaction pathway to yield the products. Preliminary studies indicate that the homoenolate pathway may be more favorable than other intermediates for product formation.
Review
Chemistry, Multidisciplinary
Tingting Li, Zhichao Jin, Yonggui Robin Chi
Summary: This review discusses N-heterocyclic carbene-catalyzed reactions for the formation of aromatic compounds, categorizing them into 4 types based on activation modes. The achievements, challenges, and future research directions in NHC-catalyzed arene construction processes are summarized. The outlook is based on the authors' opinions and knowledge on the trends of NHC organocatalysis development.
SCIENCE CHINA-CHEMISTRY
(2022)
Article
Chemistry, Organic
Yangyang Wang, Xiaoming Huang, Haojie Ji, Hongwei Zhou, Hongjie Gao, Jianfeng Xu
Summary: A quinine-derived thiourea-promoted enantioselective aza-Friedel-Crafts reaction of 3-aminobenzofurans with isatin-derived ketimines was developed, providing a variety of 3-benzofuran-3-amino-2-oxindoles bearing a quaternary stereocenter with good to excellent yields and moderate to excellent enantioselectivities. The synthetic potential of this concise and efficient protocol was demonstrated by gram-scale preparation and further transformation of the adduct to an optically pure spirocyclic oxindole.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Boqi Gu, Shuxiao Wu, Hui Xu, Wulin Yang, Zhixiang Liu, Weiping Deng
Summary: An unprecedented chiral secondary amine-catalyzed [3 + 3] annulation reaction has been developed, allowing the construction of structurally novel spiro N-heterocyclic oxindole derivatives.
CHINESE CHEMICAL LETTERS
(2021)
Article
Chemistry, Applied
Linxue Zhang, Qianqian Wu, Min Ren, Hailong Zhang, Xiaoxiang Zhang, Jinhua Liu, Zhenqian Fu
Summary: In this study, a variety of 5-indo-1-yl pyran-2-ones with an N-C axis were successfully synthesized through a carbene-catalyzed oxidative [3+3] annulation reaction. The asymmetric construction of the pyran-2-one ring from enals ensures the realization of this synthetic strategy. Furthermore, the resulting compounds were converted into axially chiral N-arylindoles with an N-C axis through a cycloaddition aromatization reaction.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Guanjie Wang, Juhui Huang, Linxue Zhang, Jinna Han, Xiaoxiang Zhang, Jie Huang, Zhenqian Fu, Wei Huang
Summary: Axially chiral molecules are widely used in various fields of chemistry, and the synthesis of axially chiral molecules catalyzed by NHCs remains underdeveloped. In this study, we successfully achieved the atroposelective synthesis of axially chiral heteroaryl-aryls using chiral NHCs as catalysts for highly enantioselective Coates-Claisen rearrangements via catalytically generated alpha, beta-unsaturated acyl azoliums. This approach enables the concise synthesis of tetra-ortho-substituted 2-pyrones with good yield and chirality control.
SCIENCE CHINA-CHEMISTRY
(2022)
Article
Chemistry, Organic
Binghao Liu, Xiao-Yong Duan, Jiahan Li, Yatong Wu, Yanting Li, Jing Qi
Summary: A new enantio- and diastereoselective reaction has been developed for the synthesis of various spirocyclic bisoxindole alkaloids. This reaction exhibits a broad substrate scope and excellent enantioselectivity, and allows for the creation of two contiguous sterically congested all-carbon quaternary stereocenters.
Article
Chemistry, Organic
Jose Cortes Vazquez, Jacqkis Davis, Vladimir N. Nesterov, Hong Wang, Weiwei Luo
Summary: A formal [3 + 3] cyclization reaction has been developed for the synthesis of 1,3,4-oxadiazinanes with generally high yields (up to 96%). The reaction, catalyzed by Sc(OTf)(3), has a broad substrate scope for both diaziridines and quinones. The synergistic activation of 1,3-dipolar diaziridines and dipolar quinones was found to be essential for enabling this reaction.
Article
Chemistry, Multidisciplinary
Pooja R. Solanke, Radhika Cinsani, Kiranmai Nayani, Prathama S. Mainkar, Srivari Chandrasekhar
Summary: A new and efficient approach to synthesizing multifunctionalized spirocyclopentenone scaffolds through Piancatelli rearrangement under metal-free conditions has been developed. This method has been successfully applied to O-, N-, and C-nucleophiles, yielding excellent results.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Mengdie Dong, Xiao-Yong Duan, Yanting Li, Binghao Liu, Jing Qi
Summary: An N-heterocyclic carbene catalyzed highly enantioselective delta-protonation of alpha,beta-gamma,delta-diunsaturated aldehydes is reported. The reaction generates extended Breslow intermediate, which undergoes [3 + 3] annulation with enamines to afford dihydropyridinones with excellent enantioselectivities.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Yuxing Cai, Jiean Chen, Yong Huang
Summary: This report describes a successful organocatalytic 1,4-alkylacylation of 1,3-enynes using a ketyl radical generated from single-electron oxidation of the Breslow intermediate as a coupling partner of allenyl radicals. The transformation exhibited remarkable tolerance to both aromatic and radical precursors.
Article
Chemistry, Inorganic & Nuclear
Keita Tanaka, Martin-Louis Y. Riu, Brian Valladares, Christopher C. Cummins
Summary: In this study, a new class of Azophosphines and N-heterocyclic iminophosphoranes (NHIPs) were successfully synthesized. The NHIPs exhibited tunability of steric demands and good basicity. The facile and scalable synthesis of NHIPs suggests their potential applications in synthetic chemistry.
INORGANIC CHEMISTRY
(2022)
