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Stereoselectivity is a major topic in organic synthesis. Intensive investigations into the role of solvents on diastereo- and enantioselective reactions, as well as temperature-dependent measurements of diastereomeric and enantiomeric ratios, have shed light on the existence of dynamic solvation effects. In this tutorial review, several examples of non-linear Eyring plots in stereoselective nucleophilic additions, cycloadditions, photochemical and enzymatic reactions are reported. Experimental data and spectroscopic analyses obtained in aliphatic and aromatic hydrocarbons, halohydrocarbons, ethers and mixtures lead to the formulation of a hypothesis on the inversion temperature phenomenon as being due to an equilibrium between distinct solute–solvent clusters, which are the real reactive species in solution. [ABSTRACT FROM AUTHOR]

The regioselective acylation of carbohydrates is of great interest in many industrial fields. Levoglucosan (1,6-anhydroglucopyranose), an anhydro-sugar easily obtainable through the pyrolytic treatment of cellulose, can be used as an excellent alternative feedstock to get chemicals of interest from renewable resources. Levoglucosan has been acylated in good yields with diverse acyl donors, such as vinyl esters and carboxylic acids with long and short chains in alternative green solvents: CH3CN, a traditional organic solvent with low ecotoxicity, and ionic liquids. The surfactant properties of 4-O-lauryl-levoglucosan have been evaluated and resulted in the range of oil soluble emulsifiers. [ABSTRACT FROM AUTHOR]

The enantioselective synthesis of (2S)-2-phenylpropanol and (2S)-2-(4-iso-butylphenyl)propanol ((S)-Ibuprofenol) has been achieved by means of Horse Liver Alcohol Dehydrogenase (HLADH) in buffered aqueous solution or buffered organic solvent mixtures; under the reaction conditions, a dynamic kinetic resolution (DKR) process was realized with good reaction yields and enantiomeric ratios. [ABSTRACT FROM AUTHOR]