Fuwei Li

Ionic Liquids as Precursors for Efficient Mesoporous Iron-Nitrogen-Doped Oxygen Reduction Electrocatalysts

A ferrocene-based ionic liquid (Fe-IL) is used as a metal-containing feedstock with a nitrogen-enriched ionic liquid (N-IL) as a compatible nitrogen content modulator to prepare a novel type of non-precious-metal-nitrogen-carbon (M-N-C) catalysts, which feature ordered mesoporous structure consisting of uniform iron oxide nanoparticles embedded into N-enriched carbons. The catalyst Fe(10) @NOMC exhibits comparable catalytic activity but superior long-term stability to 20u2005wtu2009% Pt/C for ORR with four-electron transfer pathway under alkaline conditions. Such outstanding catalytic performance is ascribed to the populated Fe (Fe3 O4 ) and N (N2) active sites with synergetic chemical coupling as well as the ordered mesoporous structure and high surface area endowed by both the versatile precursors and the synthetic strategy, which also open new avenues for the development of M-N-C catalytic materials.

Reusable ammonium salt-tagged NHC-Cu(I) complexes: preparation and catalytic application in the three component click reaction

A series of ammonium salt-tagged SIPr–Cu(I) complexes have been conveniently synthesized and characterized by NMR and HRMS. They are highly active toward the three component click reaction of benzyl bromide, NaN3 and alkyne with water as solvent at rt. Current water soluble NHC–Cu(I) catalyst could be efficiently used at least four times with an 84% isolated yield of the desired triazole in the last run.

A General Method for Palladium-Catalyzed Direct Carbonylation of Indole with Alcohol and Phenol

A novel strategy involving a first oxidative iodination and subsequent Pd(0)-catalyzed carbonylation to yield indole-3-carboxylate has been developed. It showed perfect generality to indole, alcohol, and phenol. The current methodology could also be conveniently applied to the synthesis of biologically active tropisetron from simple indole and tropine.

Palladium Nanoparticles Supported on Nitrogen‐Functionalized Active Carbon: A Stable and Highly Efficient Catalyst for the Selective Hydrogenation of Nitroarenes

Nitrogen‐functionalized active carbon‐supported ultrasmall Pd nanoparticles were conveniently prepared by using a postloading method. The Pd catalyst was highly active and selective for the hydrogenation of nitroarenes at room temperature under ambient pressure. Reducible groups such as ketone, carboxylic acid, and ester were not hydrogenated, and the corresponding anilines were obtained quantitatively. The Pd catalyst demonstrated high stability and could be reused 10u2005times without the loss of catalytic performance.

Direct N-acylation of azoles via a metal-free catalyzed oxidative cross-coupling strategy

The KI-catalyzed N-acylation of azoles via direct oxidative coupling of C-H and N-H bonds has been developed. It could be smoothly scaled up to gram synthesis of acyl azoles. The reaction occurred by the coupling of acyl radicals and azoles to form the acyl azole radical anion, followed by its further oxidation.

Pd-carbene catalyzed carbonylation reactions of aryl iodides†

A series of carbene complexes [PdBr(2)((i)Pr(2)-bimy)L] (C2-C13) with different types of co-ligands (L) have been tested for their catalytic activities in the carbonylative annulation of 2-iodophenol with phenylacetylene in DMF to afford the respective flavone 2a. Complex C12 with an N-phenylimidazole co-ligand showed the best activity and also afforded high yields when the substrate scope was extended to other aryl or pyridyl acetylenes. In addition, catalyst C12 was also efficient in the carbonylative annulation of 2-iodoaniline with acid chlorides giving the desirable 2-substituted 4H-3,1-benzoxazin-4-ones (4) in good yields. Additionally, this Pd-NHC complex also proved to be a very efficient catalyst for the hydroxycarbonylation of iodobenzene derivatives at low catalyst loading and under low CO pressure. These results demonstrate the versatility and efficiency of this phosphine-free Pd(II)-NHC complex in different types of carbonylations of aryl iodides under mild conditions.

Nickel-Catalyzed Alkynylation of a C(sp2)–H Bond Directed by an 8-Aminoquinoline Moiety

An efficient nickel catalyst system for the direct ortho C-H alkynylation of the amides has been successfully developed with the directing assistance of 8-aminoquinoline. It was found that the flexible bis(2-dimethylaminoethyl) ether (BDMAE) ligand was critical to achieve the optimized reactivity. This protocol showed good tolerance toward not only a wide range of (hetero)aryl amides but also the rarely studied α,β-unsaturated alkenyl amide. The directing amide group could be easily transformed to aldehyde or ester in high yields. Meanwhile, the removable TIPS substituent on the resultant aryl/alkenyl alkynes could be further converted to an aryl moiety through a Sila-Sonogashira coupling reaction. This Ni-catalyzed alkynylation procedure provides an alternative approach to construct a C(sp(2))-C(sp) bond.

A novel and effective Ni complex catalyst system for the coupling reactions of carbon dioxide and epoxides

The coupling of carbon dioxide and mono-substituted terminal epoxides or cyclohexene oxide to form cyclic carbonates under a Ni complex catalyst system without using additional organic solvents was achieved in excellent selectivity and TOF.

Conversion of Cellulose into Isosorbide over Bifunctional Ruthenium Nanoparticles Supported on Niobium Phosphate

Considerable effort has been applied to the development of new processes and catalysts for cellulose conversion to valuable platform chemicals. Isosorbide is among the most interesting products as it can be applied as a monomer and building block for the future replacement of fossil resource-based products. A sustainable method of isosorbide production from cellulose is presented in this work. The strategy relies on a bifunctional Ru catalyst supported on mesoporous niobium phosphate in a H2 atmosphere under pressure without further addition of any soluble acid. Over 50u2009% yield of isosorbide with almost 100u2009% cellulose conversion can be obtained in 1u2005h. The large surface area, pore size, and strong acidity of mesoporous niobium phosphate promote the hydrolysis of cellulose and dehydration of sorbitol; additionally, the appropriate size of the supported Ru nanoparticles avoids unnecessary hydrogenolysis of sorbitol. Under a cellulose/catalyst mass ratio of 43.3, the present bifunctional catalyst could be stably used up to six times, with its mesoporous structure well preserved and without detectable Ru leaching into the reaction solution.

pH-Responsive N-heterocyclic carbene copper(I) complexes: syntheses and recoverable applications in the carboxylation of arylboronic esters and benzoxazole with carbon dioxide

A pH-controlled monophasic/biphasic switchable system has been developed as a green and novel strategy for homogeneous catalyst recycling, which has been successfully applied to the Cu-NHC-catalyzed carboxylation of organoboronic esters and benzoxazole with carbon dioxide. Additionally, the present strategy could also be extended to the Ag-NHC-catalyzed carboxylation of terminal alkyne. The tertiary amine-functionalized catalysts could be used for at least four times with a slight loss of activity.