Autocatalytic photoredox Chan-Lam coupling of free diaryl sulfoximines with arylboronic acids

Nature Communications

Tian Liu¹  Qingchao Liu¹  Patrick J. Walsh²  Marisa C. Kozlowski²  Lucille A. Wells²  Tingting Meng³  Cong Wang³  Hui Zhang³  Tiezheng Jia⁴ 

[1] Department of Pharmaceutical Engineering, College of Chemical Engineering, Northwest University, Xi’an, Shanxi, China;Roy and Diana Vagelos Laboratories, Penn/Merck Laboratory for High-Throughput Experimentation, Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA;Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong, China;Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong, China;State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, China;Guangdong Provincial Key Laboratory of Catalysis, Shenzhen, Guangdong, China;

DOI  :  10.1038/s41467-021-21156-w

来源: Springer

【 摘 要 】

N-Arylation of NH-sulfoximines represents an appealing approach to access N-aryl sulfoximines, but has not been successfully applied to NH-diaryl sulfoximines. Herein, a copper-catalyzed photoredox dehydrogenative Chan-Lam coupling of free diaryl sulfoximines and arylboronic acids is described. This neutral and ligand-free coupling is initiated by ambient light-induced copper-catalyzed single-electron reduction of NH-sulfoximines. This electron transfer route circumvents the sacrificial oxidant employed in traditional Chan-Lam coupling reactions, increasing the environmental friendliness of this process. Instead, dihydrogen gas forms as a byproduct of this reaction. Mechanistic investigations also reveal a unique autocatalysis process. The C–N coupling products, N-arylated sulfoximines, serve as ligands along with NH-sulfoximine to bind to the copper species, generating the photocatalyst. DFT calculations reveal that both the NH-sulfoximine substrate and the N-aryl product can ligate the copper accounting for the observed autocatalysis. Two energetically viable stepwise pathways were located wherein the copper facilitates hydrogen atom abstraction from the NH-sulfoximine and the ethanol solvent to produce dihydrogen. The protocol described herein represents an appealing alternative strategy to the classic oxidative Chan-Lam reaction, allowing greater substrate generality as well as the elimination of byproduct formation from oxidants.

【 授权许可】

CC BY