Eric Manoury

New chiral phosphorus-containing dendrimers with ferrocenes on the periphery

Four series of new chiral ferrocenyl dendrimers (up to the 11th generation) have been synthesised and fully characterised. Electrochemical studies have been carried out on these dendrimers. In every case, one single oxidation wave has been observed, corresponding to the independent oxidation of all the ferrocene groups to ferrocenium. The chiroptical properties of the different dendrimers have been studied: the molar rotation depends only on the number of stereogenic units, independently of the generation in all series of dendrimers.

Selective synthesis of ferrocenes

Abstract We have developed a new one pot procedure for the selective functionalization of the 1′ position in ferrocenecarbaldehyde, with fair yields (up to 70%) and good regioselectivity (>90/10). Our method uses lithium N-methylpiperazide as a temporary protecting group of the aldehyde function and directing group for lithiation on the unsubstituted cyclopentadienyl ring of ferrocene. The extension of this new method with enantiomerically pure 2-substituted ferrocenecarbaldehydes provides an easy access to various enantiomerically pure 1,2,1′-trisubstituted ferrocenes with three different groups. Finally, when applying our method for the lithiation of 1,1′-ferrocenedicarbaldehyde with a chiral amine, we found a one pot synthesis of 1,2,1′,2′-tetrasubstituted C2-symmetrical ferrocenes with very high enantiomeric excesses (>99%). Furthermore, changing the experimental conditions allows us to obtain 1,2,1′-trisubstituted ferrocenes with a very good enantioselectivity (up to 96%). The first chiral enantiomerically pure 2-substituted 1,1′-(β-oxa-trimethylene)ferrocenes and the first chiral enantiomerically pure C2-symmetrical-disubstituted 1,1′-(β-oxa-trimethylene)ferrocene were also synthesized.

A Novel and Perfectly Aligned Crystal of a Ferrocenyl Chromophore Displaying High Quadratic Nonlinear Optical Bulk Efficiency

The highest nonlinear optical bulk efficiency for a 2-(4-nitrophenyl)ethenylferrocene (140 times that of urea) has been achieved for E-4 owing to a favourable noncentrosymmetrical packing in which all molecules are perfectly aligned (P1 space group).

Selective functionalization of the 1′-position in ferrocenecarbaldehyde

An efficient and selective new method for the preparation of unsymmetrical 1,1′-disubstituted ferrocenes by a one-pot procedure, starting from ferrocenecarbaldehyde, is disclosed.

HIGHLY ENANTIOSELECTIVE ONE-POT SYNTHESIS OF CHIRAL TRI- AND TETRASUBSTITUTED FERROCENES FROM 1,1'-FERROCENEDICARBALDEHYDE

Exclusively planar chirality is exhibited by the ferrocenes obtained in a highly enantioselective synthesis in which a chiral aminoamide acts as a temporary protecting/directing group. This method was used to obtain an enantiomerically pure tetrasubstituted ferrocene, which was transformed into the first C2 -symmetric disubstituted ferrocenophane [Eq. (1)].

Highly efficient reduction of ferrocenyl derivatives by borane

Abstract Borane, as a DMS or a THF complex, can efficiently reduce a large range of ferrocenyl derivatives (aldehydes, ketones, ethers, acetals, carboxylic acids, esters,…) if they bear at least one oxygen at a carbon at the α position. On the contrary, similar molecules, which contain nitrogen instead of oxygen, do not react with borane.

New phosphorus-containing dendrimers with ferrocenyl units in each layer

Abstract New phosphorus-containing dendrimers bearing ferrocenyl units within the branches were synthesised using a new 1,1’-disubstituted ferrocenyl building block. The structure of one of the synthetic intermediates was determined by X-ray analysis. In every case, one single oxidation was observed for each ferrocenic layer, corresponding to the independent oxidation of all ferrocenes within one layer to ferroceniums. The oxidation potential for a particular layer depends on substituents on ferrocenes, but not on their localisation within the dendrimers.

New chiral ferrocenyl-pyridinium salts for non-linear optics

Abstract Three enantiomerically pure chiral analogues of 4-[( E )-2-ferrocenyl-ethenyl]pyridinium iodide have been synthesized. Their bulk efficiencies in second harmonic generation (SHG) have been measured (from 0 to 0.25 times that of urea). Furthermore, the crystal structures for two of them and for the parent 4-[( E )-2-ferrocenyl-ethenyl]pyridinium iodide have been determined by X-ray diffraction studies. Crystal packing could explain the very different SHG bulk efficiencies in this family of materials.

Parahydrogen studies of H2 addition to Ir(I) complexes containing chiral phosphine-thioether ligands: implications for catalysis.

Ir(CO)[CpFe{eta5-C5H3(PPh2)CH2SR}]Cl [R = Ph and (t)Bu], containing a kappa2:P,S ligand, undergoes H2 addition across the S-Ir-CO axis under kinetic control to form two distinct diastereoisomeric products, which then rearrange via S dissociation in a process that can be hijacked for useful catalysis, but ultimately form a single diastereoisomer of the thermodynamic product where the hydride ligands are trans to chloride and phosphine.

Mono and difunctionalisation of chiral ferrocenyl bis-acetals. X-Ray crystal structure of bis-1,1′-[(2S, 4S)-(hydroxymethyl)-2-dioxane1,3]-ferrocene

Abstract The chiral 1,1′-bis-acetals, bis-1,1′-[(2S, 4S)-(hydroxymethyl)-2-dioxane1,3]-ferrocene (3) and 1,1′-bis-1,1′-[(2S, 4S)-(methoxymethyl)-2-dioxane1,3]-ferrocene (4) were synthesized. (3) was crystallographically characterised. The ortholithiation of (4) was studied in various conditions. Fair yields of monosubstituted compounds could be obtained with a complete regioselectivity in favor of the 2 position but the diastereoselectivities were moderate (up to 35%). Some disubstituted compounds can be isolated but in low yields (up to 8%). The regioselectivity is complete in favor of the 2,2′-disubstituted isomer. Only the diastereoisomer with two opposite planar chiralities is observed.