Triazolo[1,5-a]pyridyl phosphines reflecting the influence of phosphorus lone pair orientation on spectroscopic properties

A series of new triazolopyridine-based phosphines has been prepared. These compounds revealed unexpected spectroscopic patterns. In particular, the NMR spectra are highly dependent on the relative conformational preference of the phosphine substituent at C7. Here, we report on their complete NMR analysis, X-ray structures and DFT calculations that confirm the particular arrangement of the phosphorus lone pair orbital related to the substituent pattern of the chosen phosphine. © 2011 The Royal Society of Chemistry.Peer Reviewe

3-(pyridin-2-yl)[l,2,3]triazolo[l,5-a]quinoline: A theoretical and experimental analysis of ring-chain isomerisation

In the course of the synthesis of new fluorophores for molecular recognition an experimental (1H NMR) and theoretical (DFT) study of the ring-chain isomerism of 3-(pyridin-2-yl )[1,2,3]triazolo[1,5-a]quinoline derivatives (A) into 2-([1,2,3]triazolo[1,5-a]pyridin-3-yl)quinoline derivatives (B) has been carried out. The rearrangement is influenced by steric and electronic effects of the substituents present on the quinoline ring. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.Peer Reviewe

Axial Chirality Control During Suzuki−Miyaura Cross-Coupling Reactions: The tert-Butylsulfinyl Group as an Efficient Chiral Auxiliary

4 páginas, 2 figuras, 1 tabla, 3 esquemasAn efficient route to a new family of axially chiral biaryl ligands by a Suzuki−Miyaura cross-coupling reaction between ortho,ortho′-disubstituted aryl iodides bearing in ortho position a tert-butyl or p-tolylsulfinyl group and ortho-substituted phenyl boronic acids or esters is described. The comparison between the t-BuSO and p-TolSO groups as chiral controllers is reported. The modularity of the approach is demonstrated by the preparation of a variety of enantiopure axially chiral mixed S/N and S/P ligands.We thank the Dirección General de Investigación Científica y Técnica (grant No. CTQ2006-15515-CO2-01 and CTQ2007-61185), la Junta de Andalucía (grant P07-FQM-2774).Peer reviewe