56234-20-9Relevant articles and documents
Rh/TiO2-Photocatalyzed Acceptorless Dehydrogenation of N-Heterocycles upon Visible-Light Illumination
Bahnemann, Detlef W.,Balayeva, Narmina O.,Dillert, Ralf,Mamiyev, Zamin,Zheng, Nan
, p. 5542 - 5553 (2020/08/25)
TiO2 is an effective and extensively employed photocatalyst, but its practical use in visible-light-mediated organic synthesis is mainly hindered by its wide band gap energy. Herein, we have discovered that Rh-photodeposited TiO2 nanoparticles selectively dehydrogenate N-heterocyclic amines with the concomitant generation of molecular hydrogen gas in an inert atmosphere under visible light (λmax = 453 nm) illumination at room temperature. Initially, a visible-light-sensitive surface complex is formed between the N-heterocycle and TiO2. The acceptorless dehydrogenation of N-heterocycles is initiated by direct electron transfer from the HOMO energy level of the amine via the conduction band of TiO2 to the Rh nanoparticle. The reaction condition was optimized by examining different photodeposited noble metals on the surface of TiO2 and solvents, finding that Rh0 is the most efficient cocatalyst, and 2-propanol is the optimal solvent. Structurally diverse N-heterocycles such as tetrahydroquinolines, tetrahydroisoquinolines, indolines, and others bearing electron-deficient as well as electron-rich substituents underwent the dehydrogenation in good to excellent yields. The amount of released hydrogen gas evinces that only the N-heterocyclic amines are oxidized rather than the dispersant. This developed method demonstrates how UV-active TiO2 can be employed in visible-light-induced synthetic dehydrogenation of amines and simultaneous hydrogen storage applications.
Rhodium-Catalyzed Interconversion of Quinolinyl Ketones with Boronic Acids via C-C Bond Activation
Dennis, Joseph M.,Compagner, Chad T.,Dorn, Stanna K.,Johnson, Jeffrey B.
, p. 3334 - 3337 (2016/07/26)
A rhodium-catalyzed cross-coupling of aryl and aliphatic quinolinyl ketones with boronic acids has been developed. Proceeding via quinoline-directed carbon-carbon σ bond activation, the transformation demonstrates tolerance of a range of functional groups
Exploring the Catalytic Reactivity of Nickel Phosphine-Phosphite Complexes
Kampmann, Sven S.,Man, Nikki Y. T.,McKinley, Allan J.,Koutsantonis, George A.,Stewart, Scott G.
, p. 1842 - 1853 (2015/12/26)
In this study, we present an investigation into various nickel phosphite and phosphite-phosphine complexes for use in the Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions and the ammonia arylation reaction. In these coupling reactions, it was discovered that the Ni[P(OEt)3]4, (dppf)Ni[P(OPh)3]2, and (binap)Ni[P(OPh)3]2 catalysts were the most effective. In addition, an optimisation process for these catalytic systems as well as functional group compatibility are discussed.
