Pierre Le Gendre - Academia.edu (original) (raw)

Uploads

Papers by Pierre Le Gendre

Tetrahedron Letters, Nov 1, 2006

Conjugated dienes are able to react as 1,2-or 1,4-dicarbanions by coordination on Ti(II) moiety. ... more Conjugated dienes are able to react as 1,2-or 1,4-dicarbanions by coordination on Ti(II) moiety. These two possibilities are exemplified in this letter with isoprene, myrcene and several aldehydes to give 1,4-and 1,6-diols. When allowed to react with esters at room temperature, the titanium-diene complexes lead to cyclopentenol derivatives. Surprisingly, when this reaction is performed at lower temperature (À40°C), allylic ketones are formed with high regio and diastereoselectivities.

Reference EPFL-CONF-198653View record in Web of Science Record created on 2014-05-02, modified on... more Reference EPFL-CONF-198653View record in Web of Science Record created on 2014-05-02, modified on 2017-12-03

We present herein preliminary results on the use of Ti-Ru bimetallic catalyst systems in Kharasch... more We present herein preliminary results on the use of Ti-Ru bimetallic catalyst systems in Kharasch chemistry and atom transfer radical polymerisatio

Inorganic Chemistry, May 2, 2022

Ti-imido complex [TiCl(N t Bu)(BIPP)] (1; BIPP = bis(iminophosphoranyl)phosphide ligand) reacts w... more Ti-imido complex [TiCl(N t Bu)(BIPP)] (1; BIPP = bis(iminophosphoranyl)phosphide ligand) reacts with terminal alkynes R-C≡CH (R = phenyl, isopropenyl, cyclopropyl, 2-pyridyl) via P-P bond cleavage of the BIPP ligand. The resulting complexes [TiCl(NPN')(NPhPPh2)] (2a-d) contain a pincer-type NPN' phosphide ligand that incorporates the terminal alkyne and the imido ligand from complex 1. Complexes 2a-d feature two chiral centers (Ti and P) with interdependent absolute configurations, thus they are formed stereoselectively. Complex 2a (R = phenyl) undergoes chloride abstraction with [Et3SiHSiEt3][B(C6F5)4], yielding [Ti(NPN')(NPhPPh2)][B(C6F5)4] (3). Complex 3 is a moderately active and stereoselective initiator for the ring-opening polymerization of rac-lactide. Complex 3 activates the C=O bond of 4-iodobenzaldehyde to give complex 4 as a single diastereomer despite the presence of three chiral centers. Complex 3 undergoes transmetallation with SbCl3, yielding [Sb(NPN')][B(C6F5)4] (5) and

Current Organic Synthesis, May 1, 2012

Inorganic Chemistry, Dec 21, 2022

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Applied Organometallic Chemistry, May 16, 2014

The influence of hydrogen pressure on the hydrosilylation of ketones catalyzed by [((S)-SYNPHOS)R... more The influence of hydrogen pressure on the hydrosilylation of ketones catalyzed by [((S)-SYNPHOS)Rh(nbd)]OTf has been studied. We have notably demonstrated that hydrogen significantly affected the outcome of the reaction while not being consumed as stoichiometric reducing agent. In THF, diethyl ether or toluene, the hydrogen pressure exceedingly accelerated the hydrosilylation reaction and preserved or even improved the enantioselectivity of the process. In CH 2 Cl 2 , the rhodium catalyst also showed generally higher catalytic activity under hydrogen pressure. Most serendipitously, several ketones were found to give products of absolute opposite configuration upon performing the hydrosilylation under argon atmosphere or under hydrogen pressure.

Current Organic Synthesis, Nov 1, 2012

Organometallics, May 13, 2015

ABSTRACT A new family of cationic Ti complexes 4′ with a pendant phosphine of general formula [Cp... more ABSTRACT A new family of cationic Ti complexes 4′ with a pendant phosphine of general formula [CpCpPTiOAr][BPh4] (Cp = η5-C5H5; CpP = η5-C5H4(CMe2)PR2) has been prepared in four steps from 6,6-dimethylfulvene. These complexes were designed to behave as Ti based frustrated Lewis pairs (FLPs). The key synthetic step is a reduction-oxidation sequence from [CpCpPTiClOAr] complexes 3 using lithium phosphide salts as the reductants and ferricinium tetraphenylborate as the oxidant. Four complexes have been structurally characterized by X-ray diffraction and show elongated Ti-P bonds, above 2.60 Å. One complex (4b′: OAr = 2,6-Me2C6H3; PR2 = PCy2) reacted with benzaldehyde to form a typical FLP activation product. Complex 4b′ also reacted with 2 equiv of trans-chalcone to form a 10-membered Ti phosphonium macrocycle (6b′) by extrusion of 6,6-dimethylfulvene.

Aza-BODIPYs are an increasingly studied class of fluorophores. They can be seen as an "aza-D... more Aza-BODIPYs are an increasingly studied class of fluorophores. They can be seen as an "aza-DIPY" ligand rigidified by a metalloid, a boron atom. Based on this idea, a series of complexes of group 13 metals (aluminum and gallium) have been synthesized and characterized. Impact of the metal and of the nature of the substituents of aza-DIPY core were investigated. The photophysical and electrochemical properties were determined and an X-ray structure of an azaGaDIPY was obtained. These data reveal that azaGaDIPY and azaAlDIPY exhibit significant red-shifted fluorescence compared to their analogue aza-BODIPY. Their emission can go up to 800 nm for the maximum emission length and up to NIR-II for the emission tail. This, associated with their electrochemical stability (no metal release whether oxidized or reduced) make them a promising class of fluorophores for optical medical imaging. Moreover, X-ray structure and molecular modeling studies have shown that this red shift seems...

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

European Journal of Inorganic Chemistry, 2018

New Journal of Chemistry, 2018

The introduction of a benzoate ligand dramatically increases the ruthenium uptake in cells, leadi... more The introduction of a benzoate ligand dramatically increases the ruthenium uptake in cells, leading to a low micromolar IC50.

Arkivoc, 2015

Chiral and achiral silylphosphine-boranes were prepared in high yields by reaction of phosphide b... more Chiral and achiral silylphosphine-boranes were prepared in high yields by reaction of phosphide boranes with halogenosilanes. Their reaction at room temperature with Michael acceptors afforded 1,4-addition products as silylenol ether or ketone derivatives in good to excellent yields. In the case of the 2,3-dihalogeno-maleimides, the double addition of silylphosphine-borane led to the corresponding trans-diphosphine-boranes in 86% yield. Noteworthy, the reaction of Pchirogenic silylphosphine-boranes with enones afforded the phospha-Michael adducts without racemization at the P-center. While the silylphosphine-boranes have been scarcely described so far, these compounds demonstrate their great interest for the synthesis of chiral and achiral functionalized organophosphorus compounds.

Dalton Transactions, 2015

New (C^N) cyclometallated Au(iii) complexes with cytotoxic properties shown to be potent inhibito... more New (C^N) cyclometallated Au(iii) complexes with cytotoxic properties shown to be potent inhibitors of the zinc finger protein PARP-1.