A new G-(H2L)-Pd heterogeneous catalyst has been prepared via a self-assembly process consisting in the spontaneous adsorption, in water at room temperature, of a macrocyclic H2L ligand on graphene (G) (G + H2L = G-(H2L)), followed by decoration of the macrocycle with Pd2+ ions (G-(H2L) + Pd2+ = G-(H2L)-Pd) under the same mild conditions. This supramolecular approach is a sustainable (green) procedure that preserves the special characteristics of graphene and furnishes an efficient catalyst for the Cu-free Sonogashira cross coupling reaction between iodobenzene and phenylacetylene. Indeed, G-(H2L)-Pd shows an excellent conversion (90%) of reactants into diphenylacetylene under mild conditions (50 °C, water, aerobic atmosphere, 14 h). The catalyst proved to be reusable for at least four cycles, although decreasing yields down to 50% were observed.
Microporous polymers with built-in triphenylphosphine palladium exhibit highly efficient catalytic activity for cross-coupling reactions of benzyl chloride under mild conditions.
An efficient catalyst-free radical cross-coupling reaction between aromatic aldehydes and sulfoximines was developed. The reaction took place in the presence of N-bromosuccinimide as the radical initiator under microwave irradiation to afford the corresponding acylated sulfoximines in moderate to excellent yields (27 examples). This protocol proved to be rapid, easy to handle, and applicable to a broad scope of substrates.
An efficient catalyst-free system composed of ammonia borane in water or alcohol was developed to selectively convert biomass-derived feedstock into four value-added products under extremely mild conditions.
A mild and efficient catalyst-free method for the rapid synthesis at room temperature of 3-thiomethylated oxindole derivatives has been achieved via the Michael addition of aryl thiols to ring and 1-substituted 3-(2,2,2-trifluoroethylidene)oxindoles in dichloromethane. The method was applicable to a wide range of thiols and variously substituted 3-(2,2,2-trifluoroethylidene)oxindoles under mild conditions as demonstrated by the synthesis in high yields with good diastereoselectivities of 30 3-thiomethylated oxindoles bearing a trifluoromethyl group.
A highly efficient, catalyst-free and one-pot procedure for the direct synthesis of amides from aldehydes and amines under mild conditions has been developed.
A convenient and efficient chiral CuFe2O4@SiO2-Mn(III) Ch.salen nanocatalyst has been
developed for the C-N cross-coupling reactions of aryl halides/ phenylboronic acid with N-heterocyclic
compounds in water and/or DMSO under mild conditions. The catalyst could be applied for the
N-arylation of a variety of nitrogen-containing heterocycles with aryl chlorides, bromides, iodides and
phenylboronic acid under mild conditions. Moderate to good yields were achieved for all substrates.
The structure of catalyst was characterized using various techniques including FT-IR, FE-SEM, EDX,
XRD, TEM and TGA. The catalyst can be simply recovered and reused for several times without significant
loss of activity.
A New Heterogeneous Catalyst Obtained via Supramolecular Decoration of Graphene with a Pd2+ Azamacrocyclic Complex