An Electrochemical Study of Bis(cyclopentadienyl)titanium(IV) Dichloride in the Presence of Magnesium Ions, Amides or Alkynes

International audienceIn tetrahydrofuran, the electrochemical reduction of Cp2TiIVCl2 (2 mM) generated three titanium(III) complexes which were in equilibrium: [Cp2TiCl2]•−, [Cp2TiCl]• and (Cp2TiCl)2. Although the anion radical [Cp2TiCl2]•− was the main species produced under these conditions, cyclic voltammetry investigations clearly showed that the proportion of the three electrogenerated TiIII complexes can be modified as a function of the amounts of chloride ion present in the solution. Accordingly, the presence of Mg2+ ions, which led to the consumption of chloride ions through the formation of MgCl2, favoured the formation of [Cp2TiCl]• and, consequently, of the corresponding dimer (Cp2TiCl)2. The electrochemical behaviours of Cp2TiIVCl2 and of the electrogenerated low-valent Ti complexes were also investigated in the presence of amide and alkyne derivatives. Under these conditions, titanium complexes could not only interact with the amide carbonyl group, but also with the alkyne triple bond, provided the latter was not sterically hindered. Interestingly, the carbonyl group and the triple bond had antagonist effects on redox properties of titanium(III) complexes

Access to New Endoperoxide Derivatives by Electrochemical Oxidation of Substituted 3-Azabicyclo[4.1.0]hept-4-enes.

International audienceA series of substituted 3-azabicyclo[4.1.0]hept-4-ene derivatives were prepared and analysed by cyclic voltammetry. Preparative aerobic electrochemical oxidation reactions were then carried out. Three original endoperoxides were isolated, characterised and subjected to antimalarial and cytotoxicity activity assays