Michel Maumy

Copper(I)-induced addition of amines to unactivated nitriles: The first general one-step synthesis of alkyl amidines.

Abstract Cu(I)Cl promotes the condensation of acetonitrile 1a and benzonitrile 1b with primary and secondary amines 2a-g into amidines 3a-j under mild conditions, in high to quantitative yields. Stoichiometric formation of Cu(I)-amidines complexes allows to control the degree of substitution of resulting amidines.

Esters are effective co-catalysts in copper-catalyzed methanolysis of aryl bromides

Abstract Rate of copper(I)-catalyzed substitution of aryl bromides into methyl-aryl ethers by methoxide ion is greatly enhanced in presence of esters. Soluble copper(I) complexes 2, arising from tetrahedral adducts 1 of methoxide onto esters, are likely responsible for this improvement.

Ortho-hydroxylation selective des phenols : I - vers un modele chimique simple des tyrosinases

Abstract The oxydation of cuprous phenoxides by molecular oxygen gives rise to c and ortho-benzoquinones. Such a new reaction provides a mechanistic approach to tyrosinase catalyzed oxidation of phenols.

Electrochemical polymerization of several salen-type complexes. Kinetic studies in the microsecond time range

Abstract The first stages of the electrochemical polymerization of several salen-type complexes were studied by fast cyclic voltammetry on an ultramicroelectrode. In several cases, it was possible to observe the first electrogenerated intermediate and to measure its formal potential. The polymerization process was found to be very fast and to occur in the 10 microsecond time range or faster.

Asymmetric synthesis by copper-catalyzed decarboxylation of phenylmalonic diacids and hemiesters

Abstract The first asymmetric decarboxylation of monoalkyl phenylmalonates (Z = CO 2 Et) and a novel asymmetric decarboxylation of malonic diacids (Z = CO 2 H) have been achieved by a very mild catalysis with Cu I and a chiral alkaloid.

Oxydation selective en para des phenols par un complexe cuivrique oxydant

Abstract Oxidation of phenols by molecular oxygen in the presence of the μ-oxo cupric catalyst Cu 4 Cl 4 O 2 (CH 3 -CN) 3 ( A ), can be selectively directed to give either oxidative coupling or para-hydroxylation (p-quinols or p-quinones) products by the choice of the ( A )/(phenol) ratio. The mechanism is discussed and a -OH ligand transfer from Cu II to the phenolic para position is proposed.

Ortho-hydroxylation selective des phenols : II - un nouveau systeme catalytique a caractere preparatif.

Abstract A direct synthetic transformation of phenols into copper(II) catecholates (i.e. catechols) is described, which involves a copper-catalyzed activation of molecular oxygen. The mechanism and scope of this new reaction are discussed.

Copper-mediated α-hydroxylation of N-salicyloyl-glycine. A model for peptidyl-glycine α-amidating monooxygenase (PAM)

Abstract Title compound 1 is selectively hydroxytated in α position by three distinct copper- containing oxidant systems, involving dioxygen, peroxide anion or trimethylamine oxide. Trivalent copper is likely the key intermediate in this first reported model for the PHM activity of enzyme PAM.

Electrochemical behaviour of iron(III) salen and poly(iron–salen). Application to the electrocatalytic reduction of hydrogen peroxide and oxygen

Abstract The electropolymerisation of the iron(III) salen complex is reported, as well as the electrochemical behaviour of the monomer. High scan rate cyclic voltammetry allows us to calculate the lifetime of the cation radical generated during oxidation. Although the films are more difficult to prepare than several other poly(metal–salen) films (e.g. with nickel or copper), poly(iron–salen) can be well characterised by electrochemistry, either in organic or aqueous medium. The efficiency of the films towards the catalytic electroreduction of hydrogen peroxide and oxygen has been tested, and a different kinetic behaviour has been observed for both substrates, with a much greater efficiency in the case of oxygen.

Electrochemical synthesis and structural studies of copolymers based on the electrooxidation of pyrrole and some salen compounds

We present here the first studies on copolymer layers obtained from electrosynthesis of pyrrole and salen compounds. This work comes into the field of modified electrodes for sensoring applications. We investigated this electro-copolymerization because the coupling occurs by radical cation (RC) coupling for both compounds. The electrochemical behavior was studied by cyclic voltammetry, spectroelectrochemistry and in situ electron spin resonance (ESR); quantitative characterization was performed with electron dispersive spectroscopy and mass spectrometry (Maldi-Tof). In the case of the copolymer prepared with little pyrrole (versus salen) in the starting solution, the ESR data gave no typical PPy signal although cyclic voltammograms (CVs) were completely different from those of poly(salen). The composition of the layers is estimated with good approximation and this is evidently an interesting material for sensoring applications such as gas (vapor) or heavy metal sensors.