Continuous Gas-Phase Hydroformylation of Propene with CO2 Using SILP Catalysts

Hydroformylation is an important process for the synthesis of aldehydes and alcohols in the chemical industry. Although this process uses toxic CO as one of the reactants, some types of Ru complex catalysts have been known to replace CO with CO2 as a reactant in hydroformylation. Herein, we report the continuous hydroformylation of propene with CO2, heterogeneously catalyzed by supported Ru complexes on silica using ionic liquids [i.e., supported ionic liquid-phase (SILP) catalysts] in a flow reactor. When the reaction was carried out at 170 degrees C, 8.6 MPa, and gas hourly space velocity (GHSV) of 1.13 x 10(3) h(-1) using the SILP catalyst prepared from Ru-3(CO)(12), 1-ethyl-3-methylimidazolium chloride, and silica, the conversion of propene was 81.6% and the selectivity of hydroformylation was 66.1%. Kinetic analysis showed that the reaction rates of CO formation and hydroformylation were near-identical at 170 degrees C, indicating that the CO formed by the reverse water-gas shift reaction was readily used for the subsequent hydroformylation reaction. ESI-MS analysis of the ionic liquid phase showed the formation of trinuclear and mononuclear Ru complexes, and a plausible reaction mechanism was proposed based on these findings

Reverse water gas shift reaction using supported ionic liquid phase catalysts

The reverse water gas shift reaction (RWGSR) using a supported ionic liquid-phase (SILP) catalyst consisting of Ru catalyst, ionic liquid (1-butyl-3-methylimidazolium chloride ([C(4)mim]Cl)), and porous silica gel support, was investigated. The catalytic activity of the SILP catalyst toward RWGSR strongly depends on the kind of Ru catalyst and amount of IL. Among the three kinds of Ru catalysts ([RuCl2(CO)(3)](2), Ru-3(CO)(12), and RuC13), [RuCl2(CO)(3)](2) exhibits the best catalytic activity. Brunauer Emmett Teller (BET) surface area analysis and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analyses of the SILP catalyst based on [RuCl2(CO)(3)](2) and [C(4)mim]Cl revealed that both the solvation of the active catalytic Ru species and the surface area of the ionic liquid phase strongly affect catalytic activity. Hence, these factors help to determine the optimum amount of [C(4)mim]Cl in the SILP catalyst. The resulting SILP catalyst, with an optimum constitution, exhibited greater catalytic activity than the homogeneous system in which the same amounts of [RuCl2(CO)(3)](2) and [C(4)mim]Cl were employed. Catalytically active Ru species during RWGSR in both systems were investigated by means of electrospray ionization-mass spectrometry (ESI-MS). Interestingly, the rate-determining step in the two systems was different, implying that the silica support lowers the activation energy of the protonation reaction in the catalytic cycle. Therefore, the facilitation of the RWGSR by a SILP catalyst system can be realized by good mass transport, derived from the large surface area, as well as the effect of the silica support on activation energy. Furthermore, 20 cycles of the RWGSR using the SILP catalyst were accomplished

Solid acid-catalyzed one-step synthesis of oleacein from oleuropein

Abstract In this study, we developed a new synthetic strategy to convert secoiridoid glucosides into unique dialdehydic compounds using solid acid catalysts. Specifically, we succeeded in the direct synthesis of oleacein, a rare component of extra-virgin olive oil, from oleuropein, which is abundant in olive leaves. Whereas the conventional total synthesis of oleacein from lyxose requires more than 10 steps, these solid acid catalysts enabled the one-step synthesis of oleacein from oleuropein. A key step in this synthesis was the selective hydrolysis of methyl ester. Density functional theory calculations at the B3LYP/631+G (d) level of theory revealed the formation of a tetrahedral intermediate bonded to one H2O molecule. These solid acid catalysts were easily recovered and reused at least five times by simple cleaning. Importantly, this synthetic procedure was not only applicable to other secoiridoid glucosides, but could also be employed for the corresponding scale-up reaction using oleuropein extracted from olive leaves as the starting material

Elucidation of the Potential Hair Growth-Promoting Effect of Botryococcus terribilis, Its Novel Compound Methylated-Meijicoccene, and C32 Botryococcene on Cultured Hair Follicle Dermal Papilla Cells Using DNA Microarray Gene Expression Analysis

A person’s quality of life can be adversely affected by hair loss. Microalgae are widely recognized for their abundance and rich functional components. Here, we evaluated the hair growth effect of a green alga, Botryococcus terribilis (B. terribilis), in vitro using hair follicle dermal papilla cells (HFDPCs). We isolated two types of cells from B. terribilis—green and orange cells, obtained from two different culture conditions. Microarray and real time-PCR results revealed that both cell types stimulated the expression of several pathways and genes associated with different aspect of the hair follicle cycle. Additionally, we demonstrated B. terribilis’ effect on collagen and keratin synthesis and inflammation reduction. We successfully isolated a novel compound, methylated-meijicoccene (me-meijicoccene), and C32 botryococcene from B. terribilis to validate their promising effects. Our study revealed that treatment with the two compounds had no cytotoxic effect on HFDPCs and significantly enhanced the gene expression levels of hair growth markers at low concentrations. Our study provides the first evidence of the underlying hair growth promoting effect of B. terribilis and its novel compound, me-meijicoccene, and C32 botryococcene