Synthesis of New bis 1-Substituted 1H-Tetrazoles via Efficient Heterocyclizations from Symmetric Dianilines, Methyl Orthoester, and Sodium Azide

The synthesis and characterization of three new bis 1-substituted 1H-tetrazoles are described. Two products were synthesized in a single step via a direct heterocyclization of primary amines, methyl orthoester (trymethyl orthoformate), and sodium azide in 30% and 91% yields, respectively. Besides, another one was prepared via a three-step synthetic strategy: SNAr (32%), nitro-group reduction (66%), and primary amine heterocyclization (83%), yielding 18%, overall. The aim behind the synthesis of new tetrazole-containing products is to construct novel MOF-like structures to evaluate their gas capture properties (CO2, CO, and SO2) under relative humidity conditions.

Encapsulation of Metal Nanoparticles within Metal–Organic Frameworks for the Reduction of Nitro Compounds

Nitro group reduction is a reaction of a considerable importance for the preparation of bulk chemicals and in organic synthesis. There are reports in the literature showing that incorporation of metal nanoparticles (MNPs) inside metal–organic frameworks (MOFs) is a suitable strategy to develop catalysts for these reactions. Some of the examples reported in the literature have shown activity data confirming the superior performance of MNPs inside MOFs. In the present review, the existing literature reports have been grouped depending on whether these MNPs correspond to a single metal or they are alloys. The final section of this review summarizes the state of the art and forecasts future developments in the field.

Magnetically separable core–shell iron oxide@nickel nanoparticles as high-performance recyclable catalysts for chemoselective reduction of nitroaromatics

A magnetically separable core–shell iron oxide@nickel nanocatalyst was synthesized, characterized and applied for the aromatic nitro group reduction.

Effect of Solvent Polarity Properties on the Selectivity and Activity for 3,4-Dichloronitrobenzene Hydrogenation over Pd/C Catalyst

Several representative solvents classified in three categories: 1) aprotic apolar solvents: 2) protic solvents; 3) aprotic polar solvents were chosen to investigate the effect on the catalytic activity and selectivity for the selective hydrogenation of 3,4-dichloronitrobenzene (3,4-DCNB) over Pd/C catalyst. The solvent polarity increases the hydrogenation rate apparently, but also increases the selectivity to 3-chloroaniline and 4-chloroaniline from dehalogenation reaction. The solvents with the high polarity and hydrogen-bond donation capability can generate the strong interaction and the H-bond with nitro group of 3,4-DCNB, and then promote the activation and polarization of nitro group. However, on basis of the result of water as solvent, the higher hydrogenation rate in polarity solvents, to a larger extent, may be attributed to the increase of the amount of reactive chemisorbed hydrogen resulting from the dissociative chemisorption of aprotic polar solvents over the activated metal surface. At the same time, this is why the selectivity to 3-chloroaniline and 4-chloroaniline from dehalogenation reaction increase obviously with the increase of solvent polarity, because the amount of reactive chemisorbed hydrogen on the catalytic activated sites exceeds the needs of nitro group reduction and then surplus hydrogen reacts with the C-X bond.