0000000001304814
AUTHOR
Etienne Bertrand
showing 9 related works from this author
Ligands P-stéréogéniques dérivés du calix[4]arène. Synthèses et applications en catalyse asymétrique
2010
We were interested in synthesis of P-stereogenic ligands derived from calix[4]arene and in their application in asymmetric catalysis. Mono et diphosphines were prepared on the upper rim of the macrocyle starting from the mono or dianion of the calix[4]arene and chlorophosphines borane or the oxazaphospholidine borane complex. The best selectivity was obtained by reaction of the dianion with the oxazaphospholidine borane complex leading to a bisaminophosphine borane. After acidolysis with HCl giving the corresponding bischlorophosphine and reaction with organolithium reagents, diphosphines diborane were obtained with good yields (40 à 60 %). X-ray structures of the prepared ligands confirmed…
Enantioselective Hydrogenation Catalysis Aided by a σ-Bonded Calix[4]arene to a P-Chirogenic Aminophosphane Phosphinite Rhodium Complex
2010
The first P-chirogenic aminophosphane−phosphinite (AMP*P) ligand (4a) supported on the upper rim of a calix[4]arene moiety was synthesized in two steps using the ephedrine methodology. Ligand 4a wa...
P-Chirogenic Phosphines Supported by Calix[4]arene: New Insight into Palladium-Catalyzed Asymmetric Allylic Substitution
2013
The first P-chirogenic mono- and diphosphine ligands supported on the upper rim of a calix[4]arene moiety were synthesized using the ephedrine methodology. The lithiated calix[4]arene mono- and dianions both react with the oxazaphospholidine–borane, prepared from ephedrine, to afford regio- and stereoselectively the corresponding calix[4]arenyl aminophosphine–boranes, by cleavage of the heterocyclic ring at the P–O bond position. Subsequent reactions with HCl and then organolithium reagent and finally decomplexation with DABCO lead to the corresponding calix[4]arenyl mono- or diphosphines. Both enantiomers of the calix[4]arenyl phosphines were obtained either by using (+)- or (−)-ephedrine …
Evaluation of the local site effects in the upper and middle Aterno valley
2009
In the months following the April 6th, 2009, L’Aquila earthquake, several Italian and foreign research institutions installed dozens of seismic stations to monitor more than 100 localities with the aim of studying the local site effects in the epicentral area (upper and middle Aterno valley). The stations (accelerometers and velocimeters) have been deployed inside or very close to the inhabited areas. Among the investigated sites there are Onna, where almost the totality of the buildings collapsed, and the historic centre of L’Aquila, both towns suffering many casualties. The preliminary results for the examined sites show an extreme variability of ground motion and significant amplificatio…
Revisiting Vs30 as a proxy parameter for site effects: a case study using KIKNET data
2011
The local geology can strongly affect the seismic ground motion at the surface. One standard index used to classify local site effects is the average shear wave velocity in the first 30 meters, namely Vs30. The higher the Vs30 the stiffer the material is and therefore less amplification is expected. However, this index does not map the complexity of the velocity at depth. Indeed, some sites may have close Vs30 values, but quite different velocity distribution at depth. In this study, we propose the ratio between the average shear wave velocity up to depths having at least 800 m/s and Vs30. This ratio gives information about the velocity distribution at depth. Lower ratios mean stronger simi…
CCDC 952665: Experimental Crystal Structure Determination
2013
Related Article: Naima Khiri-Meribout, Etienne Bertrand, Jérôme Bayardon, Marie-Joëlle Eymin, Yoann Rousselin, Hélène Cattey, Daniel Fortin, Pierre D. Harvey, and Sylvain Jugé|2013|Organometallics|32|2827|doi:10.1021/om400229p
CCDC 952664: Experimental Crystal Structure Determination
2013
Related Article: Naima Khiri-Meribout, Etienne Bertrand, Jérôme Bayardon, Marie-Joëlle Eymin, Yoann Rousselin, Hélène Cattey, Daniel Fortin, Pierre D. Harvey, and Sylvain Jugé|2013|Organometallics|32|2827|doi:10.1021/om400229p
CCDC 952663: Experimental Crystal Structure Determination
2013
Related Article: Naima Khiri-Meribout, Etienne Bertrand, Jérôme Bayardon, Marie-Joëlle Eymin, Yoann Rousselin, Hélène Cattey, Daniel Fortin, Pierre D. Harvey, and Sylvain Jugé|2013|Organometallics|32|2827|doi:10.1021/om400229p
CCDC 952662: Experimental Crystal Structure Determination
2013
Related Article: Naima Khiri-Meribout, Etienne Bertrand, Jérôme Bayardon, Marie-Joëlle Eymin, Yoann Rousselin, Hélène Cattey, Daniel Fortin, Pierre D. Harvey, and Sylvain Jugé|2013|Organometallics|32|2827|doi:10.1021/om400229p