612-57-7Relevant articles and documents
Highly chemoselective deoxygenation of N-heterocyclic: N -oxides under transition metal-free conditions
Kim, Se Hyun,An, Ju Hyeon,Lee, Jun Hee
supporting information, p. 3735 - 3742 (2021/05/04)
Because their site-selective C-H functionalizations are now considered one of the most useful tools for synthesizing various N-heterocyclic compounds, the highly chemoselective deoxygenation of densely functionalized N-heterocyclic N-oxides has received much attention from the synthetic chemistry community. Here, we provide a protocol for the highly chemoselective deoxygenation of various functionalized N-oxides under visible light-mediated photoredox conditions with Na2-eosin Y as an organophotocatalyst. Mechanistic studies imply that the excited state of the organophotocatalyst is reductively quenched by Hantzsch esters. This operationally simple technique tolerates a wide range of functional groups and allows high-yield, multigram-scale deoxygenation. This journal is
Metal–Organic Layers Hierarchically Integrate Three Synergistic Active Sites for Tandem Catalysis
Quan, Yangjian,Lan, Guangxu,Shi, Wenjie,Xu, Ziwan,Fan, Yingjie,You, Eric,Jiang, Xiaomin,Wang, Cheng,Lin, Wenbin
supporting information, p. 3115 - 3120 (2020/12/09)
We report the design of a bifunctional metal–organic layer (MOL), Hf12-Ru-Co, composed of [Ru(DBB)(bpy)2]2+ [DBB-Ru, DBB=4,4′-di(4-benzoato)-2,2′-bipyridine; bpy=2,2′-bipyridine] connecting ligand as a photosensitizer and Co(dmgH)2(PPA)Cl (PPA-Co, dmgH=dimethylglyoxime; PPA=4-pyridinepropionic acid) on the Hf12 secondary building unit (SBU) as a hydrogen-transfer catalyst. Hf12-Ru-Co efficiently catalyzed acceptorless dehydrogenation of indolines and tetrahydroquinolines to afford indoles and quinolones. We extended this strategy to prepare Hf12-Ru-Co-OTf MOL with a [Ru(DBB)(bpy)2]2+ photosensitizer and Hf12 SBU capped with triflate as strong Lewis acids and PPA-Co as a hydrogen transfer catalyst. With three synergistic active sites, Hf12-Ru-Co-OTf competently catalyzed dehydrogenative tandem transformations of indolines with alkenes or aldehydes to afford 3-alkylindoles and bisindolylmethanes with turnover numbers of up to 500 and 460, respectively, illustrating the potential use of MOLs in constructing novel multifunctional heterogeneous catalysts.
Covalent Organic Frameworks toward Diverse Photocatalytic Aerobic Oxidations
Liu, Shuyang,Tian, Miao,Bu, Xiubin,Tian, Hua,Yang, Xiaobo
supporting information, p. 7738 - 7744 (2021/05/07)
Photoactive two-dimensional covalent organic frameworks (2D-COFs) have become promising heterogenous photocatalysts in visible-light-driven organic transformations. Herein, a visible-light-driven selective aerobic oxidation of various small organic molecules by using 2D-COFs as the photocatalyst was developed. In this protocol, due to the remarkable photocatalytic capability of hydrazone-based 2D-COF-1 on molecular oxygen activation, a wide range of amides, quinolones, heterocyclic compounds, and sulfoxides were obtained with high efficiency and excellent functional group tolerance under very mild reaction conditions. Furthermore, benefiting from the inherent advantage of heterogenous photocatalysis, prominent sustainability and easy photocatalyst recyclability, a drug molecule (modafinil) and an oxidized mustard gas simulant (2-chloroethyl ethyl sulfoxide) were selectively and easily obtained in scale-up reactions. Mechanistic investigations were conducted using radical quenching experiments and in situ ESR spectroscopy, all corroborating the proposed role of 2D-COF-1 in photocatalytic cycle.
