Asymmetric Aldol-Tishchenko Reaction of Sulfinimines.

Methods for the preparation of 1,3-amino alcohols and their derivatives containing two stereogenic centers usually involve a two-step installation of the chiral centers. An aldol-Tishchenko reaction of chiral sulfinimines which involves the first reported reduction of a C═N in this type of reaction is described. Two and even three chiral centers can be installed in one synthetic step, affording anti-1,3-amino alcohols in good diastereo- and enantioselectivity.

The asymmetric alkylation of dimethylhydrazones; intermolecular chirality transfer using sparteine as chiral ligand.

The asymmetric alkylation of ketones represents a fundamental transformation in organic chemistry. Chiral auxiliaries have been used almost exclusively for this transformation. Herein we describe a strategy for the generation of enantiomerically enriched α-alkylated ketones up to an er of 83 : 17, using a chiral ligand protocol.

Structure-function analysis of the C-3 position in analogues of microbial behavioural modulators HHQ and PQS.

2-Heptyl-3-hydroxy-4-quinolone (PQS) and its precursor 2-heptyl-4-quinolone (HHQ) are key signalling molecules of the important nosocomial pathogen Pseudomonas aeruginosa. We have recently reported an interkingdom dimension to these molecules, influencing key virulence traits in a broad spectrum of microbial species and in the human pathogenic yeast Candida albicans. For the first time, targeted chemical derivatisation of the C-3 position was undertaken to investigate the structural and molecular properties underpinning the biological activity of these compounds in P.

Analysis of Pseudomonas quinolone signal and other bacterial signalling molecules using capillaries coated with highly charged polyelectrolyte monolayers and boron doped diamond electrode.

Coated capillary electrophoresis equipped with a boron doped diamond (BDD) electrode was developed for analysis of chemically synthesised 2-heptyl-3-hydroxy-4-quinolone (HHQ), 2-heptyl-3-hydroxy-4-quinolone (PQS), and 2-methyl analogues. Detection was then extended to biological samples. PQS and its biological precursor, HHQ, are two key regulators of bacterial cooperative behaviour known as quorum sensing in the nosocomial pathogen Pseudomonas aeruginosa.

The Pseudomonas quinolone signal (PQS), and its precursor HHQ, modulate interspecies and interkingdom behaviour.

The Pseudomonas quinolone signal (PQS), and its precursor 2-heptyl-4-quinolone (HHQ), play a key role in coordinating virulence in the important cystic fibrosis pathogen Pseudomonas aeruginosa. The discovery of HHQ analogues in Burkholderia and other microorganisms led us to investigate the possibility that these compounds can influence interspecies behaviour. We found that surface-associated phenotypes were repressed in Gram-positive and Gram-negative bacteria as well as in pathogenic yeast in response to PQS and HHQ.