Shu-Ping Luo

Photocatalytic Water Reduction with Copper‐Based Photosensitizers: A Noble‐Metal‐Free System

Of noble descent: a fully noble-metal-free system for the photocatalytic reduction of water at room temperature has been developed. This system consists of Cu(I) complexes as photosensitizers and [Fe(3)(CO)(12)] as the water-reduction catalyst. The novel Cu-based photosensitizers are relatively inexpensive, readily available from commercial sources, and stable to ambient conditions, thus making them an attractive alternative to the widely used noble-metal based systems.

In situ enamine activation in aqueous salt solutions: highly efficient asymmetric organocatalytic Diels-Alder reaction of cyclohexenones with nitroolefins.

Deep-sea Diels-Alder: The asymmetric organocatalytic Diels-Alder reaction of cyclohexenones with aromatic nitroolefins can be carried out in seawater and brine. The reaction proceeds by an in situ enamine activation involving a one-step concerted addition pathway (see scheme).

A noble-metal-free system for photocatalytic hydrogen production from water.

A series of heteroleptic copper(I) complexes with bidentate PP and NN chelate ligands was prepared and successfully applied as photosensitizers in the light-driven production of hydrogen, by using [Fe3(CO)12] as a water-reduction catalyst (WRC). These systems efficiently reduces protons from water/THF/triethylamine mixtures, in which the amine serves as a sacrificial electron donor (SR). Turnover numbers (for H) up to 1330 were obtained with these fully noble-metal-free systems. The new complexes were electrochemically and photophysically characterized. They exhibited a correlation between the lifetimes of the MLCT excited state and their efficiency as photosensitizers in proton-reduction systems. Within these experiments, considerably long excited-state lifetimes of up to 54 μs were observed. Quenching studies with the SR, in the presence and absence of the WRC, showed that intramolecular deactivation was more efficient in the former case, thus suggesting the predominance of an oxidative quenching pathway.

Fischer indole synthesis catalyzed by novel SO3H-functionalized ionic liquids in water

Novel SO3H-functionalized ionic liquids bearing two alkyl sulfonic acid groups in the imidazolium cations were designed and successfully applied as catalysts for the one-pot Fischer indole synthesis in water medium. The sequence of the catalytic activity observed in the transformation was in good agreement with the Bronsted acidity order determined by the Hammett method. Various types of indoles from single-carbonyl ketones/aldehydes and cyclohexandiones were provided in 68–96% yields using the catalytic system of [(HSO3-p)2im][HSO4]/H2O. The indole products could be conveniently separated from the reaction mixture by filtration and the dissolved catalyst could be regenerated by treatment with a strongly acidic cation exchange resin, which meant the whole process was performed in water without using any organic solvents.

Photocatalytic Hydrogen Production with Copper Photosensitizer–Titanium Dioxide Composites

A series of heteroleptic copper photosensitizers [(

Complexes of Ionic Liquids with Poly(ethylene glycol)s

\widehat{PP}

One‐Pot Organocatalytic Asymmetric Synthesis of 3‐Nitro‐1,2‐dihydroquinolines by a Dual‐Activation Protocol

)Cu(

Copper-Based Photosensitisers in Water Reduction: A More Efficient In Situ Formed System and Improved Mechanistic Understanding.

\widehat{NN}

Highly Efficient AILs/L‐Proline Synergistic Catalyzed Three‐Component Asymmetric Mannich Reaction

(SO3Na)2)]+ containing sulfonate anchor groups is described. In the presence of titanium dioxide they form composites, which are active photosensitizers in the light driven reduction of protons. Further stabilization of these systems is achieved by encapsulation within a plasma‐polymerized allylamine (PPAAm) layer. The resulting PPAAm‐CuPS‐TiO2‐composites exhibit a strong absorption in the visible region of the light. Photocatalytic hydrogen production is performed by using only non‐noble metals. In the presence of an iron reduction catalyst a maximum turnover number of 2452 is obtained.

Structure-Activated Copper Photosensitisers for Photocatalytic Water Reduction

The self-assembly behavior of ionic liquids with acyclic polyethers was studied. The cations of 1-alkyl-3-methylimidazolium salts and 1-alkylpyridinium salts could form complexes at a ratio of 1:1 with poly(ethylene glycol)-800 (PEG800) and poly(propylene glycol)-1000 (PPG1000) in which the chain length was suitable to wrap around the cations. On the basis of the investigation by NMR, mass spectrometry, UV-vis spectroscopy, and TG analysis, the formation and characteristics of the novel complexes were discussed.