Solvent- and Additive-Free Dehydrogenation of N-Heterocycles with Oxygen Catalyzed by Polyoxovanadate-Based Metal-Organic Frameworks

Tian，Hongrui; Pan，Yingying; Xu，Na; Miao，Jun; Zheng，Zhiping

2023-12-11

10.1021/acs.inorgchem.3c03174

Inorganic Chemistry   影响因子和分区

0020-1669

1520-510X

N-heteroarenes are a family of organics with significant chemical and pharmaceutical applications. They are generally prepared by the catalytic oxidative dehydrogenation (ODH) of partially saturated N-heterocycles. In this work, we prepare and demonstrate the catalytic ODH applications of two polyoxovanadate-based metal-organic frameworks of the general formula {[M(bibp)][VO]}·HO (M = Ni 1, Co 2; bibp = 4,4′-bis(imidazol-1-ylmethyl)biphenyl). They are based on nonprecious metals, need no additives or organic solvents typically required for catalytic ODH, and utilize molecular O as the oxidant, thus possessing all the traits desirable for practical catalysis. Catalyst 1 shows tolerance for a range of substrates with different electronic and steric features, including 2,3-dihydro-1H-indole and tetrahydroquinolines substituted with various functional groups. Mechanistic studies supported primarily by evidence from electron paramagnetic resonance and X-ray photoelectron spectra suggest that the V sites in 1 are catalytically responsible, first enabling the formation of the substrate-based radical species by a single electron transfer event while being converted into its mixed-valence form, followed by the production of the superoxide radical anion (O) upon contact with O. The reaction mixture containing O and the initially formed substrate-based radical then undergoes a series of steps, including the hydrogen abstraction and formation of the hydroperoxyl radical, the production and tautomerization of the partially dehydrogenated intermediate, and finally a repeating cycle of the aforementioned steps, to achieve the high-yield conversion of substrates to the corresponding N-heteroarenes.

EI ; SCI

英语

NI论文

第一 ; 通讯

20234915175927

Additives ; Catalysis ; Dehydrogenation ; Free radical reactions ; Organometallics ; Oxygen ; Paramagnetic resonance ; Photoelectron spectroscopy ; Reaction intermediates

Magnetism: Basic Concepts and Phenomena:701.2 ; Chemical Reactions:802.2 ; Chemical Agents and Basic Industrial Chemicals:803 ; Chemical Products Generally:804 ; Organic Compounds:804.1

CHEMISTRY

2-s2.0-85178603752

Scopus

Department of Chemistry and Shenzhen Grubbs Institute,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China

Tian，Hongrui,Pan，Yingying,Xu，Na,et al. Solvent- and Additive-Free Dehydrogenation of N-Heterocycles with Oxygen Catalyzed by Polyoxovanadate-Based Metal-Organic Frameworks[J]. Inorganic Chemistry,2023,62(49):20228-20235.

Tian，Hongrui,Pan，Yingying,Xu，Na,Miao，Jun,&Zheng，Zhiping.(2023).Solvent- and Additive-Free Dehydrogenation of N-Heterocycles with Oxygen Catalyzed by Polyoxovanadate-Based Metal-Organic Frameworks.Inorganic Chemistry,62(49),20228-20235.

Tian，Hongrui,et al."Solvent- and Additive-Free Dehydrogenation of N-Heterocycles with Oxygen Catalyzed by Polyoxovanadate-Based Metal-Organic Frameworks".Inorganic Chemistry 62.49(2023):20228-20235.