Copper Nanoparticles from Copper Aluminum Hydrotalcite: An Efficient Catalyst for Acceptor‐ and Oxidant‐Free Dehydrogenation of Amines and Alcohols

Abstract

An efficient and simple process for the preparation of stable nanocopper(0) on alumina [Cu(0)/Al2O3] from the inorganic composite precursor copper aluminum hydrotalcite (Cu‐Al HT) by a chemical reduction method is described. Cu(0)/Al2O3 was employed as an efficient catalyst in the acceptor‐ and oxidant‐free dehydrogenation of various amines and alcohols to their corresponding dehydrogenated products in good to excellent yields. The stability of Cu(0)/Al2O3 was assessed by studying its recoverability and reusability in the dehydrogenation of amines and alcohols for up to five cycles.magnified image

Dehydrogenative Oxidation of Alcohols Catalyzed by Highly Dispersed Ruthenium Incorporated Titanium Oxide

“…In comparison with other heterogeneous catalytic systems in oxidant-free conditions (Au/CeO2, (TOF = 125 h −1 ) [7], Ag/Al2O3 (>2 h −1 ) [9], Ru/AlO(OH) (7 h −1 ) [39], Cu/hydrotalcite (1.5 h −1 ) [40], Cu/Al2O3 (8.3 h −1 ) [41]), our value is higher except for the silver nanoparticles on the hydrotalcite system (590 h −1 ) [11].…”

“…The surface area of samples was measured by Brunauer-Emmett- The turnover frequency (TOF) based on Ru for benzyl alcohol oxidation using Ru 0.01 TiO 2 amounts to 130 h −1 where the total amount of ruthenium obtained from Inductively coupled plasma mass spectrometry (ICP) data are used for TOF calculation. In comparison with other heterogeneous catalytic systems in oxidant-free conditions (Au/CeO 2 , (TOF = 125 h −1 ) [7], Ag/Al 2 O 3 (>2 h −1 ) [9], Ru/AlO(OH) (7 h −1 ) [39], Cu/hydrotalcite (1.5 h −1 ) [40], Cu/Al 2 O 3 (8.3 h −1 ) [41]), our value is higher except for the silver nanoparticles on the hydrotalcite system (590 h −1 ) [11].…”

New Gateways to the Platinum Group Metal-Catalyzed Direct Deuterium-Labeling Method Utilizing Hydrogen as a Catalyst Activator

“…However, organic solvents have been required for the reported methods. [36][37][38][39][40][41][42][43] Although the dehydrogenation of alcohols using a platinum group metal on carbon as a catalyst in H 2 O can proceed as shown in Chart 5 to give the intermediary carbonyl products, the reverse hydrogenation by the in situ-generated H 2 immediately reproduces the mother alcohols. Therefore, the suppression of the reverse hydrogenation is important to achieve the dehydrogenation of alcohols into carbonyl products.…”

ZrOCl2/nano TiO2 as an Efficient Catalyst for the One Pot Synthesis of Naphthopyranopyrimidines Under Solvent-free Conditions

“…Nanoparticles decrease reaction times, impart greater selectivity and can be easily recovered from the reaction mixture by simple filtration. [14][15][16][17][18][19] Utilizing binary supporting catalysts is a vast challenging necessity for organic chemists due to their expanding surface area. In comparison with conventional supports like solid-phase, nanoparticular matrixes have a higher catalyst loading capacity owing to their very large surface area.…”