Cascade engineered synthesis of the drug butamben (n-butyl-p-aminobenzoate), a local anaesthetic, which is used for the treatment of chronic pain, is presented here. A new multifunctional heterogeneous catalyst was synthesized, characterized and used for the direct synthesis of n-butyl-p-aminobenzoate by hydrogenation and esterification. A mixture of p-nitrobenzoic acid, n-butanol, hydrogen, acetonitrile as solvent and catalyst was used and hydrogenated in which hydrogenation precedes esterification. A series of aluminum exchanged dodecatungstophosphoric acids (DTP) (Alx-DTP; x = 0.33–1) (5–20% w/w) supported on mesocellular foam silica (MCF) were prepared. 2% Fe loaded on 15% Al0.66DTP/MCF showed the best activity for one-pot synthesis because the metal and acid sites had proper strength and distribution on MCF. Reaction mechanism and kinetic model were developed. The catalyst 2%Fe-15% Al0.66DTP/MCF was found reusable for four catalytic cycles. This work presents an interesting case of reaction engineering using multi-functional catalyst useful in synthesis of a pharmaceutical drug butamben and has potential applications in other areas.

A highly active Pd/CeO2-ZrO2-Al2O3(Pd/CZAm) catalyst was successfully fabricated by optimizing the reducibility of CZAm support through a novel precipitation method. Pd/CZAm-a (aged catalyst) could maintain a superior activity, the T90 (temperature for 90% conversion) of CO, NO and HC has decreased by 36 °C, 30 °C and 54 °C comparing with Pd/CZAc-a (reference catalyst). As characterized, the better activity of Pd/CZAm is associated closely with the advanced reducibility of CZAm support. By controlling the individual precipitation process of CZ and Al2O3 via two different precipitants, the CZAm which displays more homogeneous CZ structure, abundant surface and bulk oxygen defects manifested by XRD, Raman, XPS and TEM-EDS results has been successfully prepared without any additives and excess treatment. Then stronger interaction between CZAm and supported Pd species has been manifested by XPS, H2-TPR and CO-IR results, which prevents the sintering and decomposition of PdO species during aging process. Consequently, Pd/CZAm-a could maintain the better dispersion of Pd species and more oxidized PdO with respect to Pd/CZAc-a.

Formic acid (FA) is a versatile molecule with widespread applications in both chemical industries and renewable energy fields. However, the commercial manufacture of FA is still based on non-renewable fossil feedstock, and thus alternative methods to obtain FA from renewable resources are highly desirable and attract significant scientific attentions. Biomass represents the largest carbon resource on Earth, and various strategies including acid hydrolysis, wet oxidation and catalytic oxidation have been developing to transform biomass resources into FA with relatively high yield and selectivity. Meanwhile, carbon dioxide (CO2) as an inexpensive and widely available C1 platform compound, is also a potential resource to produce FA via hydrogenation by different strategies such as chemical, photochemical and electrochemical catalysis. In this review, FA production from biomass resources especially cellulosic biomass will be systematically summarized according to the transformation methods. Following this, recent progresses in the CO2 valorization to generate FA will be generally illustrated. Finally, the catalytic dehydrogenation of FA to generate hydrogen as a clean and renewable energy fuel will be concisely mentioned since it exemplifies the critical role of FA in future energy restructure tactics.

Two new Schiff-based cyclopalladated aryl imine catalysts (denoted as Fc-Pd and B-Pd) were prepared and their ordered self-assembled molecular monolayers (called as Si@F-Pd and Si@B-Pd) were fabricated. Their catalytic performances were evaluated using Suzuki coupling reaction as a templet with water as solvent, in which the structure on their catalytic properties and mechanism were systematic studied. Si@F-Pd and Si@B-Pd exhibited higher catalytic active with higher turnover number (TON) (149095 and 173214) and could be recycled at least 8 time and 6 time, respectively. The molecular structure and geometry of the catalyst was an important factor for their catalytic performance and stability, in which that large steric and structure made it easy to alter the electronic environment and structure, regulate the state of catalytic active surface which are contributed to their high catalytic activity. It was the fact that the electron rich of Pd may be formed by transferring electrons from ligand to Pd which became more nucleophilic for enhancing the facile oxidative addition with aryl halides. The catalytic mechanism proceeded a quasi-homogenous property on the surface in the form of leaching and re-deposition manner. Si@Fc-Pd acted as catalytic sites (surface) and sources or likely a reservoir for active species leaching, which formed a cycling state of equilibrium. It was clarified that the homogeneous and heterogeneous catalysis occurred at the same period on the surface and in solution, which was confirmed by hot-filtration, poison text, three-phase text, AFM, CV, XPS and ReactIR.

Manganese and cobalt metals-based mixed oxide (MnCo2O4) spinels supported ruthenium (Ru) nanoparticles, Ru/MnCo2O4, is found to be an active catalyst to execute outstandingly the hydrogenation of 5-hydroxymethylfurfural (HMF) to produce two useful furan diols such as 2,5-bis(hydroxymethyl)furan (BHMF) and 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF) in highly selective fashion without any additive. It could found that Ru/MnCo2O4 was able to catalyze not only the oxidation but also the reduction of HMF due to the redox properties of the MnCo2O4. Moreover, the characterization details responsible for the high activity of this catalyst in the hydrogenation of HMF were investigated by several spectroscopic methods. In order to maximize the products yield and HMF conversion, the effect of reaction variables such as time, temperature, pressure, and various metal oxides supported Ru nanoparticles was also investigated. Furthermore, the reusability tests exhibited that Ru/MnCo2O4 catalyst could be reused at several consecutive cycles, retaining almost its original activity.

A mechanistic exploration of the liquid phase hydrogenation of the aromatic cyanohydrin mandelonitrile (C6H5CH(OH)CH2CN) over a carbon supported Pd catalyst to produce the primary amine, phenethylamine (C6H5CH2CH2NH2) is conducted. Prior examination showed the reaction to involve the production of the ketone intermediate 2-aminoacetophenone (C6H5C(O)CH2NH2), formed as a consequence of the presence of an acid catalysed tautomeric side reaction. The corresponding deuteration reaction, reported here and analysed by multinuclear NMR spectroscopy and mass spectrometry, is employed to further investigate accessible pathways. Examination of the resultant product distribution of the deuteration, and the location of deuterium incorporation establishes the role of a hydroxy-imine species as a key reaction intermediate. In addition, the acid catalysed tautomerism to the ketone is shown to be a reversible side reaction, but also a contributor to desired product formation. Moreover, an order for the three critical hydrogen consuming steps in phenethylamine formation is established. Hydrogenation of the nitrile functionality to afford the hydroxy-imine precedes hydrogenolysis of the hydroxyl group, with the final step being hydrogenation of the imine to form the target product, phenethylamine.

Selenium-incorporated polymeric carbon nitride (PCN)-catalyzed epoxidation reaction of β-ionone was developed for producing (E)-4-(2,2,6-trimethyl-7-oxabicyclo[4.1.0]heptan-1-yl)but-3-en-2-one, which was a popular spice in perfume production as well as the key intermediate for the total synthesis of the highly demanded phytohormone abscisic acid. The reaction employed water as cheap, safe and green precursor of H2O2 oxidant and utilized visible light as the driving force. It was found that introducing Se into the material from Se powder significantly enhanced the catalytic activity of PCN owing to the predominantly increased specific surface area of the catalyst (37.7 m²/g of PCN-Se vs. 16.6 m²/g of simple PCN) and the oxygen carrier catalyst features of incorporated Se. The highly electropositive Se sites facilitated their electrophilic additions with the thermodynamically unfavourable endocyclic C=C of β-ionone, affording a regio-specific access to useful epoxide product. This is the first report of the unique PCN-Se relay catalysis procedure.