The toxicities of a series of glycerol mono-, di-, and trialkyl ethers against Vibrio fischeri bacteria have been determined. A systematic study has been carried out and the possible structure-toxicity relationships have been discussed using different QSAR models. Inhibition of bioluminescence after 30 minutes of exposure shows relatively low toxicity for many of the glycerol derived chemicals studied. Results indicate, that, as a general rule, the ecotoxicity increases as the length and number of substituents do. However, if the size of the molecule increases, an extra substituent at position 2, makes the toxicity lower than that of the corresponding analogues.

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Azabis(oxazoline)-cobalt(II) complexes have been tested in multiphasic catalytic systems for enantioselective conjugate reduction of (E)-3-phenylbut-2-enoate with NaBH 4 . Immobilization by 10 electrostatic interactions with laponite clay leads to excellent results in the first run, as a consequence of the role of the clay as anion. However most of the reaction takes place in solution due to leaching of active complex, and the solids are not reusable. Covalent immobilization to Merrifield's resin does not allow reaching the high enantioselectivity obtained in solution and homogeneous catalysts are again not reusable. Only the use of biphasic liquid systems allows an 15 efficient recovery of the catalyst. The combination of a new ditopic ligand and 1,3-bis(2,2,2-trifluoroethoxy)propan-2-ol as a solvent for the catalyst phase is optimal to recycle the catalytic system with 90-96% ee for 5 runs. IntroductionThe selective reduction of double bonds in -unsaturated 20 carbonylic compounds has became one important tool for the synthesis of organic compounds. Hence many systems have been described to improve this selective process.1 The use of metal hydrides as well as the combination of hydrides, such as sodium borohydride or aluminium hydrides, and transition 25 metal salts have allowed reducing selectively double bonds conjugated with electron-withdrawing groups.2 However, there are very few examples in the literature about the asymmetric version of this type of reductions.3 One of these examples was reported by Pfaltz and co-workers who 30 described the use of semicorrin-cobalt complexes in the enantioselective reduction of -unsaturated esters and amides with sodium borohydride obtaining high enantioselectivities. 4 Afterwards, other chiral cobalt complexes were used in the reduction of acrylamides with 35 very good results. 5 Recently, Reiser and co-workers have described the use of azabis(oxazoline)-Co complexes which proved to be highly efficient and selective in the reduction of esters, lactames and amides with NaBH 4 . has emerged as a powerful tool in order to improve the applicability of enantioselective processes, due to the easier catalyst separation in comparison with the analogous homogeneous counterparts. However, this is not the only advantage that would justify the use, in some cases, of 45 supported systems prepared by easy non-covalent immobilization methods. It has been shown that immobilized catalysts can afford additional advantages related to site-isolation or to the possibility of using them as true multitask catalysts.9 More recently, it has been shown that the support can be used as an active part of the enantioselection process, 10 leading to 55 catalytic reactions with improved stereoselectivity 11 or even with a reversal in the stereochemical result in comparison with the behavior of the same catalysts in solution. 12 The easy separation and purification of the catalyst, as well as the improved activity and selectivity are clearly desirable 60 objectives of Green Chemistry.In this pap...

A physicochemical study of 5-methylfurfural and tetrahydrofurfuryl alcohol (density, speed of sound, refractive index, surface tension, static permittivity, and viscosity) has been carried out under atmospheric pressure at temperatures from (278.15 to 338.15) K, while the vapor pressure was determined over a temperature range from (303.15 to 453.15) K. Furthermore, the pρT behavior has also been assessed over a temperature range from (283.15 to 338.15) K and a pressure range from (0.1 to 60.0) MPa. Results indicate that although values of speed of sound, molar free volume, and viscosity of tetrahydrofurfuryl alcohol are higher than for the rest of the furfural family, the free volume/molar volume ratio is smaller for 5-methylfurfural, indicating a better packing. Furthermore, VOC character of the studied compounds is smaller than some traditional solvents.