Oxygen-implanted MoS2 nanosheets promoting quinoline synthesis from nitroarenes and aliphatic alcohols via an integrated oxidation transfer hydrogenation-cyclization mechanism

• Published in: Green chemistry : an international journal and green chemistry resource : GC Vol. 24; no. 4; pp. 1704 - 1713
• Main Authors: Zhang, Chaofeng, Gao, Zhuyan, Ren, Puning, Lu, Jianmin, Huang, Zhipeng, Su, Kaiyi, Zhang, Shichao, Mu, Junju, Wang, Feng
• Format: Journal Article
• Language: English
• Published: CAMBRIDGE Royal Soc Chemistry 21.02.2022; Royal Society of Chemistry
• Subjects: Alcohols; Aliphatic alcohols; Anaerobic conditions; Catalysis; Catalysts; Chemical synthesis; Chemistry; Chemistry, Multidisciplinary; Ethanol; Green & Sustainable Science & Technology; Green chemistry; Hydrogenation; Molybdenum disulfide; Nanosheets; Nitrobenzene; Organic compounds; Oxidation; Oxygen; Physical Sciences; Quinoline; Quinolines; Regeneration; Science & Technology; Science & Technology - Other Topics; MILD; CHEMOSELECTIVE TRANSFER HYDROGENATION; SELECTIVE HYDROGENATION; CONVERSION; QUINALDINES; POT PHOTOCATALYTIC SYNTHESIS; HETEROGENEOUS CATALYST; TITANIA
• ISSN: 1463-9262; 1463-9270
• DOI: 10.1039/d1gc04058h

We herein report that MoS2 with oxygen-implanting modification (O-MoS2) can work as a multifunctional catalyst to achieve the one-pot quinoline synthesis from basic nitroarenes and aliphatic alcohols. Different from common knowledge that the application of MoS2-based catalysts and above quinoline synthesis need anaerobic conditions, we conduct the heterogeneous catalysis under an unusual air atmosphere. Catalyst characterization and experimental results indicate that the MoOx clusters implanted in the MoS2 skeleton, not the coordinatively unsaturated Mo sites (CUS Mo), dominate the generation of quinolines. By overturning the catalysis perception that O-2 adsorption on MoSx can deactivate the MoS2-based catalysts using an efficient method for in situ healing of the MoOx structure in O-MoS2 and protecting the O-MoS2 catalyst by inhibiting unwanted MoOx elimination with extra H*, we innovatively introduce O-2 into the quinoline synthesis. The robust O-MoS2 can be consecutively used ten times without regeneration and it offers 69-75% yields of 2-methylquinoline from nitrobenzene and ethanol. Furthermore, different from the traditional transfer hydrogenation-condensation mechanism, an integrated oxidation-transfer hydrogenation-cyclization mechanism is proposed over the O-MoS2 catalyst.