Biomedical subjects

Benoît Laleu

Publications and source records attributed to Benoît Laleu.

5 recordsLinked to original sources

PubMed2007

Effective HPLC resolution of [4]heterohelicenium dyes on chiral stationary phases using reversed-phase eluents.

[4]Heterohelicenium cations 1a-c adopt a twisted helical structure that renders them chiral. They are configurationally stable and their enantiomers have been resolved, for the first time, by HPLC on Chiralcel OD-RH and Chirobiotic TAG chiral stationary phases (CSPs). Chiral cations 1a-c have been resolved by HPLC using water-based eluents containing KPF(6) as additive. The elution order of the analyte enantiomers was determined by on-line CD detection, and was found to be opposite on the two CSPs. The effect of mobile phase composition and analyte structure on retention and enantioselectivity was investigated.

Chromatography, High Pressure Liquid↗

PubMed2006

Trimesitylmethylphosphonium cation. Supramolecular stereocontrol and simple enantiomerization mechanism determination.

Stereocontrol over the propeller isomerism of trimesitylmethylphosphonium cation was achieved through an ion pairing with chiral hexacoordinated phosphate anions; the asymmetric ion pairing allowed also a most simple experimental proof of the nature of the enantiomerization pathway in solution (two-ring flip).

Journal Article↗

PubMed2006

Pummerer fragmentation vs. pummerer rearrangement: a mechanistic analysis.

Depending upon the nature of the substituent at the beta-position of the sulfoxide moiety, a Pummerer reaction can be oriented "at will" towards Calpha-H (rearrangement) or Calpha-Cbeta (fragmentation) bond cleavage.

Journal Article↗

PubMed2005

Resolution of [4]heterohelicenium dyes with unprecedented Pummerer-like chemistry.

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Journal Article↗

PubMed2003

Bent structure and dynamic stereochemistry of chiral acridinium cations.

Chiral acridinium cations, easily prepared by reaction of enantiopure primary amines and tris(2,6-dimethoxy)trityl cation, display restricted rotations around the C(sp(3))-N(sp(2)) bond. A bending of the aromatic backbone and "out-of-plane" displacements of C(9) and N(10) atoms are enforced if bulky amines are introduced.

Journal Article↗