Tamis Darbre

The metal coordinating ability of a bipyridine ligand at the core of a peptide dendrimer was found to be controlled by the nature of amino acids placed at the dendrimer periphery, with coordination being promoted by anionic residues and inhibited by cationic residues; heterotrimers with mixed charges were preferentially formed.

Two new ω‐(1H‐pyrrol‐3‐yl)alkanoic acids 8a,b and the corresponding amines 9a,b were prepared on large scale in 41–51 and 27–39% overall yield, respectively, starting from N‐phenylsulfonyl‐protected pyrrole. The target compounds contain the desired functional groups for attachment of biomolecules such as proteins. During synthesis, an unprecedented partial reduction of the pyrrole ring with NaBH₃CN in glacial AcOH was observed, for which a plausible mechanism is proposed (Scheme 3).

Zn complexes of proline, lysine and arginine are efficient catalysts for the aldol addition of p-nitrobenzaldehyde and acetone in aqueous medium, giving quantitative yields and enantiomeric excesses up to 56% with 5 mol% of the catalysts at room temperature.

Zn complexes of proline, lysine and arginine are efficient catalysts for the aldol addition of p-nitrobenzaldehyde and acetone in aqueous medium, giving quantitative yields and enantiomeric excesses up to 56% with 5 mol% of the catalysts at room temperature.