Andrzej Wolan

Synthesis of arylboronates by the palladium catalysed cross-coupling reaction in ionic liquids

The palladium catalysed cross-coupling reaction of aryl iodides and bromides with pinacolborane in 1,3-dialkylimidazolium tetrafluoroborates and hexafluorophosphates producing arylboronates is described.

Syntheses with organoboranes. XIII. Synthesis of ω-(4-bromophenyl)alkanoic acids and their borylation

Abstract ω-(4-Bromophenyl)alkanoic acids 2c – e were obtained from 1-bromo-4-alkenylbenzenes 5c – e by hydroboration–thermal isomerization–oxidation. Their esters 11c – e were transformed in good yields into the corresponding boronates 12c – e by the cross-coupling reaction with 4,4,5,5,4′,4′,5′,5′-octamethyl[2,2′]bi[[1,3,2]dioxaborolanyl] ( 10 ) in an ionic liquid, [bmim][BF 4 ]. The use of pinacolborane for the coupling reaction in the ionic liquid gave debromination products, and low yields of 12c – e . Ethyl 3-(4-bromophenyl)propanoate ( 7c ) was transformed into ethyl 3-(4-[1,3,2]dioxaborolanyl)propanoate ( 9c ) by the cross-coupling with [2,2′]bi[[1,3,2]dioxaborinanyl].

Candida antarctica lipase B catalyzed enantioselective acylation of pyrimidine acyclonucleoside

Abstract The influence of solvent and acyl group donor on selectivity of the transesterification reaction of 1-[1′,3′-dihydroxy-2′-propoxymethyl]-5-methyluracil, a structural analogue of ganciclovir was examined. Lipase (EC 3.1.1.3) B from Candida antarctica (CALB) enabled desymmetrization of prochiral hydroxyl groups when 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF6]) was used as a reaction medium. It was observed that CALB was up to 2.7–4 times more enantioselective in the ionic liquid [Bmim][PF6] than in conventional organic solvents.

The Effect of Reactive Ionic Liquid or Plasticizer Incorporation on the Physicochemical and Transport Properties of Cellulose Acetate Propionate-Based Membranes

Pervaporation is a membrane-separation technique which uses polymeric and/or ceramic membranes. In the case of pervaporation processes applied to dehydration, the membrane should transport water molecules preferentially. Reactive ionic liquid (RIL) (3-(1,3-diethoxy-1,3-dioxopropan-2-yl)-1-methyl-1H-imidazol-3-ium) was used to prepare novel dense cellulose acetate propionate (CAP) based membranes, applying the phase-inversion method. The designed polymer-ionic liquid system contained ionic liquid partially linked to the polymeric structure via the transesterification reaction. The various physicochemical, mechanical, equilibrium and transport properties of CAP-RIL membranes were determined and compared with the properties of CAP membranes modified with plasticizers, i.e., tributyl citrate (TBC) and acetyl tributyl citrate (ATBC). Thermogravimetric analysis (TGA) testified that CAP-RIL membranes as well as CAP membranes modified with TBC and ATBC are thermally stable up to at least 120 °C. Tensile tests of the membranes revealed improved mechanical properties reflected by reduced brittleness and increased elongation at break achieved for CAP-RIL membranes in contrast to pristine CAP membranes. RIL plasticizes the CAP matrix, and CAP-RIL membranes possess preferable mechanical properties in comparison to membranes with other plasticizers investigated. The incorporation of RIL into CAP membranes tuned the surface properties of the membranes, enhancing their hydrophilic character. Moreover, the addition of RIL into CAP resulted in an excellent improvement of the separation factor, in comparison to pristine CAP membranes, in pervaporation dehydration of propan-2-ol. The separation factor β increased from ca. 10 for pristine CAP membrane to ca. 380 for CAP-16.7-RIL membranes contacting an azeotropic composition of water-propan-2-ol mixture (i.e., 12 wt % water).