Development of new gold catalysts and their use in the development of new synthetic transformations
Considering the limited number of catalytic systems presently available and the fact that those are not always optimal in terms of efficiency, selectivity and stability, the aim of the current proposal, is to: 1- to develop a series of various new catalytic systems that could complement or improve those which are currently employed, 2- to study their activitiy, specificity and relative stability. <br />
The aim of the project is mainly to synthesize new gold(I) complexes by classical methods by modifying the nature of the ligand(s) carried by the gold center. These new complexes are tested as catalysts in a panel of known or designed transformations to establish their activity and compare them to known catalysts.
For this project, studies concerning the synthesis and the reactivity of gold(I) complexes possessing phosphonite type ligands have been carried out. A special interest has been brought to phosphonite ligands possessing a biaryl backbone. It was indeed postulated that these complexes might possess the steric properties of Buchwald ligands (possessing biaryl backbones) combined to the electronic properties of phosphites.
A series of biarylphosphonite ligands have been synthesized by addition of metallated biaryl derivatives on triarylphosphites. The corresponding gold(I) complexes have then been synthesized and their catalytic properties evaluated on model reactions. Promising results have been obtained more especially for the oxidative cyclization of propynylarenes. The same complexes were also shown to be powerful catalysts in a series of typically gold-catalyzed reactions.
Studies concerning the synthesis of gold(I) complexes possessing pi- acidic phosphorus based ligands derived from heterocycles are in progress. This work should lead to new complexes possesing the electronic properties of phosphite ligands with an additional greater thermal stability.
Studies on the synthesis of new carbene ligands are also underway.
G. Henrion, T. E. J. Chavas, X. Le Goff, F.Gagosz Angew. Chem. Int. Ed. 2013, 52, 6277-6282
The aim of this project is to develop new gold complexes that might be used as catalysts in organic synthesis. The proposal, which is based on the expertise of the group of Dr. F. Gagosz (CNRS/Ecole Polytechnique, France) in the field of homogeneous catalysis (more especially gold catalysis) , is composed of three main tasks. The first one is concerned with the synthesis of new achiral as well as chiral gold(I) and gold(III) complexes possessing various ligands and counter-anions. A special focus is on their characterization and their behavior (lifetime, stability, decomposition pathway) (second task). The last task deals with the evaluation of the new complexes in catalysis in terms of efficiency and/or selectivity.
Monsieur fabien gagosz (Laboratoire de synthèse Organique (DCSO)) – firstname.lastname@example.org
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
DCSO - UMR7652 Laboratoire de synthèse Organique (DCSO)
Help of the ANR 137,696 euros
Beginning and duration of the scientific project: September 2012 - 36 Months