Three-dimensional mesoporous silica with a highly dispersed palladium nanoparticles composite (PS-3) catalyst has been prepared and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, nitrogen sorption, and high resolution transmission electron microscopy. The PS-3 catalyst utilized for the first time as an efficient and reusable catalyst in the ortho-arylation of benzamides by aryl iodides has been demonstrated with the simplest amide CONH2 as a directing group. It can be successfully applied to various benzamides and aryl iodides with both electron donating and withdrawing groups. The catalyst can be simply recovered and reused several times without significant loss in catalytic activity.

A new facile synthesis of ordered mesoporous aluminosilicates has been developed and applied for the efficient catalytic synthesis of N-benzyl secondary amines under ligand and basefree conditions. The MAS(38) catalyst with a well-ordered mesoporous structure and strong acidic sites was used for acid-catalyzed organic transformations and its operational simplicity and ease of its isolation procedure make it an attractive alternative to current methodologies. N-alkyl secondary amine derivatives linked to herbicides and pharmaceuticals have been demonstrated as numerous biologically active compounds for drug discovery.[1] N-benzyl secondary amines, in particular, have attracted considerable attention from both biological and organic chemists. This is because they appear as carboxamide derivatives, which are the most prevalent structural moieties in medicinal chemistry.[2] However, despite widespread interest, the most common strategies for the production of secondary amines such as electrophilic alkylation, reductive alkylation, and amination of aryl halides, often exhibit limitations such as low selectivity toward desired secondary amines, harsh reaction conditions, and stoichiometric amounts of wasteful salts. [3,4] In addition, various expensive [Ru 3 (CO) 7 ] cluster, [Ir(COD)Cl] dimer, rhodium, and platinum transition metal complexes have been used as homogeneous catalysts for synthesizing secondary amines in the presence of base additives, which retard the commercialization of the process because of high cost and environmental concerns. [5][6][7] The use of heterogeneous catalysts [8][9][10][11][12] offers several advantages over homogeneous catalysts, including ease of separating reactants, minimal trace metal in the products, ease of handling, process control, and reusability of catalysts. These advantages can thus improve reaction processes. Therefore, developing an environmentally friendly and recyclable heterogeneous catalytic system for synthesizing secondary amines is of considerable interest. Heterogeneous catalysts such as Fe/ amino acids, Fe 3 O 4 , and Fe 3 O 4 /tBuO À have been used for the synthesis of secondary amines, [12,13] however, these systems suffer from complicated synthesis procedures and low activity compared with precious metal complexes.In recent years, mesoporous materials have demonstrated their potential in solar cells, fuel cells, and drug delivery systems. [14][15][16][17][18][19][20][21] In addition, mesoporous materials have been increasingly applied as heterogeneous catalysts in various organic transformations because of their unique structural and textural properties such as controllable pore size, uniform poresize distribution, high thermal stability, and ultrahigh specific surface area. [22,23] Among various heterogeneous catalysts, aluminosilicates have been considered useful solid catalysts because of their usage as effective catalysts in aldol, FriedelCrafts, and Diels-Alder reactions. [24,25] However, based on our knowledge, no studies have synthesized secondary amin...

Substituted guanidines were synthesized by the guanylation of amines with carbodiimides using Zn-Al hydrotalcite (Zn-Al HT) catalyst. Zn-Al HT was prepared by co-precipitation method and characterized by X-ray powder diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Raman and Thermogravimetric-Differential Thermal Analysis (TG-DTA). The heterogeneous catalyst afforded moderate to good yields (∼50-60 %) of substituted guanidines in toluene at 110 • C in 12 h. The catalyst was recovered quantitatively by simple filtration and reused for three cycles with consistent activity. The XRD and FTIR studies of the used catalyst shows no variation in the structure of the catalyst even after three recycles.

Aromatic ketones (R-Ar-CO-R′) have been prepared directly through C-C bond formation using aromatics, aryl, and alkyl acid halides to undergo Friedel-Crafts reaction over reusable and catalytically active ordered SnO 2 -SiO 2 three-dimensional mesoporous composite (PS-4) catalyst, which found to be superior to modified zeolites, functionalized MCM-41 and supported heteropolyacid catalysts.

The cover picture shows the ligand-free production of a secondary amine by using an ordered hexagonal mesoporous aluminosilicate as an effective catalyst. In their Communication, P. Srinivasu et al. report the facile synthesis of ordered mesoporous aluminosilicate catalysts for the efficient synthesis of N-benzyl secondary amines. The catalysts perform C-N bond formation between benzyl alcohol and aniline for various N-benzyl secondary amines with excellent activity. Furthermore, the catalysts are highly active and potentially reusable. Their operational simplicity and ease of isolation are an attractive alternative to previous methodologies.