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Silvia Ranieri

    Silvia Ranieri

    The Friedel-Crafts (F-C) reaction represents one of the most powerful ways for the generation of a new C-C bond between an electron-rich aromatic system and a suitable electrophile. During the last years organocatalysis demonstrated to be... more
    The Friedel-Crafts (F-C) reaction represents one of the most powerful ways for the generation of a new C-C bond between an electron-rich aromatic system and a suitable electrophile. During the last years organocatalysis demonstrated to be a suitable strategy to realize this venerable transformation in an enantioselective fashion. Exploiting the capability of primary amine catalyst to realize unique reaction pathways with elevated enantiocontrol,4 we envisioned that a new asymmetric organocascade reaction based on a Friedel-Crafts alkylation followed by acetalization between naphthols and α,β-unsaturated ketones would be feasible. Under the optimized reaction conditions, the desired products were obtained in good yields and high enantiomeric excesses Interestingly, using indenones as electrophiles, only the F-C reaction occurs in slightly longer reaction times, but also with very good results in terms of yields and enantioselectivities
    An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely... more
    An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
    An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely... more
    An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
    An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely... more
    An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
    An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely... more
    An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
    An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely... more
    An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
    An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely... more
    An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
    Indoles (II) and (V) bearing Michael acceptors at the 4-position are used in enantioselective organocatalytic cascade reactions with enals (III) and (VI).
    An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely... more
    An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
    A straightforward strategy for the synthesis of dihydroquinazolines is presented, which allows for the preparation of 3,4- and 1,4-dihydroquinazolines with different substitution patterns from 2-aminobenzylamine (2-ABA) as common... more
    A straightforward strategy for the synthesis of dihydroquinazolines is presented, which allows for the preparation of 3,4- and 1,4-dihydroquinazolines with different substitution patterns from 2-aminobenzylamine (2-ABA) as common precursor. The required functionalization of both amino groups present in 2-ABA was achieved by different routes involving selective N-acylation and cesium carbonate-mediated N-alkylation reactions, avoiding protection/deprotection steps. The heterocycles were efficiently synthesized in short reaction times by microwave-assisted ring closure of the corresponding aminoamides promoted by ethyl polyphosphate (PPE).
    Long-range bonding interactions were evaluated using variable-temperature NMR spectroscopy and suitable... more
    Long-range bonding interactions were evaluated using variable-temperature NMR spectroscopy and suitable 2'-CH2X-substituted phenylpyridines (X = Me, NMe2, OMe, F). It was found that the arylpyridyl rotational barriers were lower when electronegative atoms were bound to the α carbon of the 2' moiety. This effect was ascribed to a stabilizing interaction in the transition state due to the lone pair of the heterocyclic nitrogen with the α carbon. Computational support for this hypothesis came from CCSD(T)/6-31+G(d) calculations. Steric effects of the X moiety were ruled out by comparison of the rotational barriers of analogous biphenyls.
    Research Interests:
    4-Aryl-3-bromo-N-benzylmaleimides and 3,4-biaryl-N-benzylmaleimides have been synthesized by a modified Suzuki cross-coupling reaction from 3,4-dibromo-N-benzylmaleimide. The conformational studies by dynamic NMR and DFT calculations... more
    4-Aryl-3-bromo-N-benzylmaleimides and 3,4-biaryl-N-benzylmaleimides have been synthesized by a modified Suzuki cross-coupling reaction from 3,4-dibromo-N-benzylmaleimide. The conformational studies by dynamic NMR and DFT calculations showed that the interconversion barrier between the two available skewed conformations is under steric control. When the aryl group was a 2-methylnaphthyl, thermally stable atropisomers were isolated by enantioselective HPLC and their absolute configurations were assigned by TD-DFT simulations of the ECD spectra.
    The Shvo's catalyzed selective hydrogenation of HMF to BHMF showed substrate and product effects on the reaction rate. DFT calculation suggested the formation of several intermediates influencing the catalytic cycle.