Combining single electron transfer between a donor substrate and a catalyst-activated acceptor substrate with a stereocontrolled radical-radical recombination enables the visible-light-driven catalytic enantio- and diastereoselective synthesis of 1,2-amino alcohols from trifluoromethyl ketones and tertiary amines. With a chiral iridium complex acting as both a Lewis acid and a photoredox catalyst, enantioselectivities of up to 99% ee were achieved. A quantum yield of <1 supports the proposed catalytic cycle in which at least one photon is needed for each asymmetric C-C bond formation mediated by single electron transfer.

A homologous nanoparticle library was synthesized in which gold nanoparticles were coated with polyethylene glycol, whereby the diameter of the gold cores, as well as the thickness of the shell of polyethylene glycol, was varied. Basic physicochemical parameters of this two-dimensional nanoparticle library, such as size, ζ-potential, hydrophilicity, elasticity, and catalytic activity ,were determined. Cell uptake of selected nanoparticles with equal size yet varying thickness of the polymer shell and their effect on basic structural and functional cell parameters was determined. Data indicates that thinner, more hydrophilic coatings, combined with the partial functionalization with quaternary ammonium cations, result in a more efficient uptake, which relates to significant effects on structural and functional cell parameters.

Organic compounds isolated from diatoms contain long-chain polyamines with a propylamine backbone and variable methylation levels and chain lengths. These long-chain polyamines are thought to be one of the important classes of molecules that are responsible for the formation of the hierarchically structured silica-based cell walls of diatoms. Here we describe a synthetic route based on solid-phase peptide synthesis from which well-defined long-chain polyamines with different chain lengths, methylation patterns, and subunits can be obtained. Quantitative silica precipitation experiments together with structural information about the precipitated silica structures gained by scanning and transmission electron microscopy revealed a distinct dependence of the amount, size, and form of the silica precipitates on the molecular structure of the polyamine. Moreover, the influence of the phosphate concentration was elucidated, revealing the importance of divalent anions for the precipitation procedure. We were able to derive further insights into the precipitation properties of long-chain polyamines as functions of their hydrophobicity, protonation state, and phosphate concentration, which may pave the way for better control of the formation of nanostructured silica under ambient conditions.

A novel ruthenium catalyst is introduced which contains solely achiral ligands and acquires its chirality entirely from octahedral centrochirality. The configurationally stable catalyst is demonstrated to catalyze the alkynylation of trifluoromethyl ketones with very high enantioselectivity (up to >99% ee) at low catalyst loadings (down to 0.2 mol%).