N-Arylation of 3-Formylquinolin-2(1H)-ones Using Copper(II)-Catalyzed Chan-Lam Coupling.

3-formyl-2-quinolones have attracted the scientific community's attention because they are used as versatile building blocks in the synthesis of more complex compounds showing different and attractive biological activities. Using copper-catalyzed Chan-Lam coupling, we synthesized 32 new N-aryl-3-formyl-2-quinolone derivatives at 80 °C, in air and using inexpensive phenylboronic acids as arylating agents. 3-formyl-2-quinolones and substituted 3-formyl-2-quinolones can act as substrates, and among the products, the p-methyl derivative 9a was used as a substrate to obtain different derivatives such as alcohol, amine, nitrile, and chalcone.

Synthesis of N-Arylcytisine Derivatives Using the Copper-Catalyzed Chan-Lam Coupling.

N-Arylcytisine derivatives are quite rare. We report here a practical methodology to obtain these compounds. Using the copper-catalyzed Chan-Lam coupling, we synthesized new N-arylcytisine derivatives at room temperature, in air and using inexpensive phenylboronic acids. Cytisine and 3,5-dihalocytisines can act as substrates, and among the products, the p-Br-derivative 2r was used as a substrate to obtain biaryl derivatives under Pd-coupling conditions; ester 2j was converted into its acid and amide derivatives using classical carbodiimide conditions. This shows that the Chan-Lam cross-coupling reaction can be included as a versatile synthetic tool in the derivatization of natural products.

Hybrid organic-inorganic mononuclear lanthanoid single ion magnets.

The first family of hybrid mononuclear organic-inorganic lanthanoid complexes is reported, based on [PW11O39]7- and 1,10-phenanthroline ligands. This hybrid approach causes a dramatic improvement of the relaxation time (×1000) with a decrease of the optimal field while maintaining the Ueff of the inorganic analogues.

Substitution Effect on the Charge Transfer Processes in Organo-Imido Lindqvist-Polyoxomolybdate.

Two new aromatic organo-imido polyoxometalates with an electron donor triazole group ([n-Bu4N]2[Mo6O18NC6H4N3C2H2]) (1) and a highly conjugated fluorene ([n-Bu4N]2[Mo6O18NC13H9]) (2) have been obtained. The electrochemical and spectroscopic properties of several organo-imido systems were studied. These properties were analysed by the theoretical study of the redox potentials and by means of the excitation analysis, in order to understand the effect on the substitution of the organo-imido fragment and the effect of the interaction to a metal centre. Our results show a bathochromic shift related to the charge transfer processes induced by the increase of the conjugated character of the organic fragment. The cathodic shift obtained from the electrochemical studies reflects that the electronic communication and conjugation between the organic and inorganic fragments is the main reason of this phenomenon.

The first ReI organometallic complex with an organoimido-polyoxometalate ligand.

The spectroscopic, electrochemical and photophysical properties of the first ReI organometallic organoimido-polyoxometalate complex [n-Bu4N][Mo6O18NC6H4-CH2-N3C2H2-Re-phen(CO)3] compared with all fragments are reported. The UV-Vis spectra are analysed using experimental and theoretical tools. In contrast to the reported studies in the literature, our results show that a new more intense band is present in the spectra of the hybrid ligand obscuring the intra-polyanion charge transfer. The electrochemical results show that the strong acceptor character of the polyoxometalate fragment is quenched by the condensation of the phenyl-triazole molecule.

Crystal lattice effect on the quenching of the intracluster magnetic interaction in [V12B18O60H6](10-) polyoxometalate.

In the present work, the synthesis and structural characterization of four new polyoxovanadoborate (BVO) frameworks based on the [V12B18O60H6](10-) polyanion are reported: (NH4)8(1,3-diapH2)[V12B18O60H6]·5H2O (1), K8(NH4)2[V12B18O60H6]·18H2O (2), K10[V12B18O60H6]·10H2O (3) and K8Cs2[V12B18O60H6]·10H2O (4). A global antiferromagnetic behaviour is observed for these 10V(IV)/2V(V) mixed valence clusters. The magnetic data of 1, 2 and 3, which present different countercation environments, show that 1 is more coupled than 2 and 3. DFT calculations show that the positive charges strongly influence the polarization mechanism of the spin density of the vanadyl groups and the extent of the magnetic orbitals, therefore corroborating the experimental observation of the quenching effect of the magnetic coupling between vanadium centres of 2 and 3.