Hwimin Seo

Catalytic asymmetric synthesis of cyclopentenones from propargyl malonates and allylic acetate by successive action of homogeneous palladium(ii) and cobalt on charcoal catalysts in a one-pot reactionElectronic supplementary information (ESI) available: experimental details. See http://www.rsc.org/suppdata/cc/b1/b106836a/

The tandem action of a homogeneous chiral Pd(II) catalyst and a heterogeneous Co/C catalyst leads to a two-step one-pot highly enantioselective Pauson-Khand-type reaction.

Preparation and application of polymer-supported π-allylpalladium complex as a chiral catalyst in the asymmetric allylic alkylation

Abstract Chiral ferrocenylphosphine-imines A–D were synthesized and grafted to polystyrene to afford polymeric ligands PA–PD. Ligands A–D and PA–PD were used as ligands in the palladium-catalyzed asymmetric allylic alkylation. In the homogeneous reactions, the best result was obtained when the ligand A was used (99% yield and 82% ee). In the heterogeneous reactions, the highest ee value (73%) in the first run was obtained when PA was used as a ligand. Considering the enantioselectivity and reusability, the best result was obtained in the case of PC. The recycling of the polymer-supported π-allylpalladium catalyst gave unsatisfactory results: it can be reused three times with moderate enantioselectivities (60–70% ee).

Development of the Al2O3-supported NaNO3-Na2Mg(CO3)2 sorbent for CO2 capture with facilitated sorption kinetics at intermediate temperatures

For the development of a dry solid sorbent having quite fast CO2 sorption kinetics in an intermediate temperature range of 245–300 °C to be applicable to a riser-type fluidized bed carbonator, samples of Al2O3-supported MgCO3 (1.2 mmol/g) promoted with different molar amounts of Na2CO3 (1.2, 1.8 mmol/g) and/or NaNO3 (0.6 mmol/g) were prepared by incipient wetness pore volume impregnation. For a reference, an unsupported bulk phase sorbent of NaNO3-Na2Mg(CO3)2 was also prepared. From the sorption reaction using a gas mixture containing CO2 by 2.5–10% at 1 bar for the sorbents after their activation to MgO, Al2O3-supported sorbents were featured by their rapid carbonation kinetics in contrast to the unsupported sorbent showing a quite slow carbonation behavior. The addition of Na2CO3 to the MgCO3/Al2O3 sorbent made MgO species more reactive for the carbonation, bringing about a markedly enhanced kinetic rate and conversion, as compared with the unpromoted MgCO3/Al2O3 sorbent having a small negligible reactivity. The addition of NaNO3 to MgCO3/Al2O3 or to Na2CO3-MgCO3/Al2O3 induced the same promotional effects, but to a lesser magnitude, as observed for the Na2CO3 addition. It was also characteristic for all these MgCO3-based sorbents that initial carbonation conversions with time appeared as sigmoid curves. For the Al2O3-supported sorbent comprised of NaNO3, Na2CO3, and MgCO3 by 0.6, 1.8, and 1.2 mmols, respectively, per gram sorbent, showing the best kinetic performance, a kinetic equation capable of reflecting such sigmoid conversion behavior was established, and its applicability to a riser carbonator was examined throughout a simple model calculation based on the kinetics obtained.