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Reductive amination of cyclohexanone with benzylamine was investigated at 100 °C under 30 bar hydrogen in toluene with five different gold catalysts prepared by deposition-precipitation method and supported on TiO 2 , La 2 O 3 /TiO 2 , CeO 2 / TiO 2 , La 2 O 3 and CeO 2. Size of metallic gold varied in the range of 2.6-3.6 nm. The best catalysts in reductive amination of cyclohexanone with benzylamine were 4 wt% Au/TiO 2 and 4 wt% Au/CeO 2 /TiO 2 giving 72% and 79% yield of the desired amine. The most acidic and basic catalysts were also unselective and exhibited low activity towards imine hydrogenation. The best catalyst 4 wt% Au/CeO 2 /TiO 2 gave in reductive amination of propiophenone 56% selectivity to the corresponding amine at 20% conversion in 5 h.

ABSTRACT:The structures of TADDOL-like α-conidendrin-based chiral 1,4-diols (LIGNOLs) have been studied at molecular mechanics, Hartree-Fock (HF)/6-31G* and DFT/B3LYP/TZVP level of theory. The molecules included were 1,1-diphenyl, two diastereomers of 1,1,4-triphenyl, 1,1,4,4-tetraphenyl, and 1,1,4,4-tetramethyl 1,4-diol. Several conformers of each molecule were studied thorougly also including the entropy contributions. For the triphenyl 1,4-diols, which can form π − π interactions between phenyl rings, the DFT optimized structures differed significantly from the HF optimized ones. A property for the most stable structures, in addition to the ability to form π − π interactions, seemed to be the possibility to have the aliphatic six-membered ring in a boat conformation. For all of the studied LIGNOLs some conformers were found, where the two OH groups pointed almost to the same direction. By this an intramolecular hydrogen bond can be formed between them. The bridging hydrogen atom falls at the same place as a chelate-bonded metal ion would be situated, as in the case of the analogous molecules, TADDOLs, but only a few of these molecules would be able to work well as ligands for asymmetric catalysis.

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The electrolysis of water is popular both as lab work and as a demonstration. In this activity, the electrolysis of water in the presence of a pH indicator is used to produce text and symbols. This report describes the design of an environmentally friendly setup of a writing board utilizing the electrolysis of water in a hydrogel environment. The activity can be performed by only using chemicals and materials that are easily accessible to everyone, with no special permit needed. The writing board has been developed mainly as an outreach activity for our faculty and has been assessed during visits from upper secondary school students.