Aryl-bridged C1-symmetric oxazolinyl sulfoximines are applicable in copper-catalyzed asymmetric Mukaiyama aldol reactions with methyl pyruvate. The resulting alpha-hydroxy esters have been obtained with up to 94% ee in good yields. They contain a quaternary stereogenic center and represent valuable precursors for biologically active molecules.

2‐(2‐Aminoexthoxy)ethanol or diglycolamine (DGA) is a CO2 absorption solvent that is suitable to treat natural gas, flue gas, and biogas or landfill gas. Equilibrium CO2 solubility in concentrated aqueous DGA solvents with varying molality was measured under absorption and desorption conditions at different temperatures. Viscosity and surface tension of the solvent before absorption, after absorption, and after desorption were determined. With increasing DGA molality, CO2 loading remained constant until the number of moles of DGA exceeded the number of moles of water. For a given DGA molality, with higher CO2 loading, viscosity increased exponentially and surface tension rose with a power of two.

Bisphospholane Josiphos-type ligands were synthesized in high yields employing electrophilic and nucleophilic phospholane synthons. Full characterization data including solid-state structures of the diastereomeric ligands are reported. These ligands resulted in active and enantioselective iridium catalysts for the asymmetric hydrogenation of imines. Pronounced cooperative effects of the chiral elements within the ligand structure were observed and enantioselectivities of up to 74% ee were achieved.

Oxocarboxylic acids and esters Q 0460 C1-Symmetric Oxazolinyl Sulfoximines as Ligands in Copper-Catalyzed Asymmetric Mukaiyama Aldol Reactions. -The copper-catalyzed asymmetric Mukaiyama aldol reaction of various silyl enol ethers (I) or (IX) with methyl pyruvate (II) proceeds efficiently in the presence of an aryl-bridged oxazolinyl sulfoximine ligand (OPS) to give α-hydroxy esters containing a quaternary stereocenter (III) and (X) in up to 94% optical purity. Similarly, a vinylogous Mukaiyama aldol reaction takes place starting from siloxyfuran (XI). The aldol adducts can be transformed to biologically relevant derivatives like malic acid derivative (IV) or tetronic acid derivative (VIII). -(SEDELMEIER, J.; HAMMERER, T.; BOLM*, C.; Org. Lett. 10 (2008) 5, 917-920; Inst. Org. Chem., RWTH Aachen, D-52074 Aachen, Germany; Eng.) -Mischke 31-096

Synthesis of Phospholane-Phosphoramidite Ligands and Their Application in Asymmetric Catalysis. -Ligand PPQ shows the best performance in the hydrogenations of olefines and imines as well as in the hydroformylation of styrenes among the title ligands. -(HAMMERER, T.; LEITNER, W.; FRANCIO*, G.; ChemCatChem 7 (2015) 10, 1583-1592, http://dx.doi.org/10.1002/cctc.201500070 ; Inst. Tech. Chem. Makromol. Chem., RWTH Aachen, D-52074 Aachen, Germany; Eng.) -M. Tismer 40-025