Co-reporter:Jun Wu, Guang Gao, Peng Sun, Xiangdong Long, and Fuwei Li
ACS Catalysis November 3, 2017 Volume 7(Issue 11) pp:7890-7890
Publication Date(Web):October 11, 2017
DOI:10.1021/acscatal.7b02837
Bimetallic catalysts based on nonprecious transition metals have attracted increasing attention because of their unique synergistic effects in catalytic reactions, but the understanding of the nature of synergistic effects and their roles in a specific hydrogenation reaction remains lacking. Herein, a series of bimetallic CuxCoy/Al2O3 (x/y = 5:1, 2:1, 1:1, 1:2, 1:5) nanocomposite catalysts were fabricated via the successive calcination and reductive activation process of layered double hydroxide precursors. Their catalytic performance in the selective hydrogenation of bioderived ethyl levulinate to 1,4-pentanediol (1,4-PeD) depended sensitively on the chemical composition of bimetallic CuCo catalysts. The optimal bimetallic Cu2Co1/Al2O3 catalyst exhibited markedly improved catalytic activity and selectivity compared to monometallic Cu/Al2O3, as confirmed by its lower apparent activation energy barrier of 65.1 kJ mol–1 of the rate-determining step and its high selectivity of 93% to 1,4-PeD. Detailed characterization analyses and intrinsic catalytic studies revealed that the presence of CoOx species in the bimetallic CuxCoy/Al2O3 catalysts enhanced the metallic Cu dispersion and H2 activation ability. More importantly, the strong electronic interaction at the interface of Cu and adjacent CoOx species modified the chemical states of Cu species to create proper surface Cu0/Cu+ distributions and, particularly, provided synergic catalysis sites of Cu and electron-deficient CoOx species, which was primarily responsible for the excellent catalytic performance of bimetallic CuCo catalysts. The bimetallic CuCo catalysts exhibited good stability in both batch and fixed-bed continuous flow reactions. Furthermore, present CuCo nanocomposite catalyst could be applied to the highly selective hydrogenation of other carboxylic esters and lactones to synthesize valuable C4, C5, and C6 diols.Keywords: CuCo nanocomposite; diol monomer; layered double hydroxide; selective hydrogenation; synergetic catalysis;
Co-reporter:Pan Li, Jingjing Zhao, Xinjian Li, and Fuwei Li
The Journal of Organic Chemistry May 5, 2017 Volume 82(Issue 9) pp:4569-4569
Publication Date(Web):April 6, 2017
DOI:10.1021/acs.joc.7b00112
A novel and efficient synthesis of functionalized oxazoles from 2-amidodihydrofurans has been achieved by alkali-induced intramolecular C–O bond cleavage and formation using air as a green oxidant. Moreover, these functionalized oxazoles could be readily transformed into the corresponding oxazole-substituted pyrazoles and 2H-azirines.
Co-reporter:Jinlei Li;Guoliang Liu;Lijun Shi;Qi Xing
Green Chemistry (1999-Present) 2017 vol. 19(Issue 24) pp:5782-5788
Publication Date(Web):2017/12/11
DOI:10.1039/C7GC02335A
The development of heterogeneous, cost-effective and environmentally benign catalysts to construct CC bonds is highly desirable. We report here Co@N-doped carbon nanotubes (Co@NCNT) as a catalyst for a novel synthesis of styryl sulfides via dehydrogenative coupling of benzyl alcohols and DMSO under anaerobic conditions. This reaction maintains high atom efficiency as the CC bond is formed without the cracking of the C–S bond. We proposed that Co modified N-doped carbon sites are the active sites, different from traditionally believed metal centers for dehydrogenative C–C coupling. Moreover, the Co@NCNT catalyst could be easily separated and recycled for at least six runs. This work opens up a new application of metal–N–C catalysts in CC bond-forming reactions in synthetic chemistry.
Co-reporter:Xinjian Li;Qi Xing;Pan Li;Jingjing Zhao
European Journal of Organic Chemistry 2017 Volume 2017(Issue 3) pp:618-625
Publication Date(Web):2017/01/18
DOI:10.1002/ejoc.201601343
An atom-economic and efficient approach to the synthesis of 2-arylquinolines has been developed. The protocol involves an iron-catalysed cascade N-alkylation/aerobic oxidation/Povarov reaction, and the desired quinolines were prepared in moderate to excellent yields from readily accessible anilines, aldehydes, and EtOH/nPrOH, with water as the only side-product. The aniline substrates also act as a recyclable transfer medium for EtOH/nPrOH through an in-situ N-alkylation/oxidation process. This makes EtOH/nPrOH an economical and environmentally friendly precursor of alkenes as well as the solvent.
Co-reporter:Qi Xing;Hui Lv;Chungu Xia
Chemical Communications 2017 vol. 53(Issue 51) pp:6914-6917
Publication Date(Web):2017/06/22
DOI:10.1039/C7CC03274A
An efficient palladium-catalyzed oxidative aminocarbonylation of azoles has been developed. This system allows for intermolecular carbonylative cross-coupling of aromatic C(sp2)–H bonds with simple amines, which has often been asked for, but has not been realized so far. It provides a straightforward approach to a variety of azol-2-amides.
Co-reporter:Jinlei Li, Guoliang Liu, Xiangdong Long, Guang Gao, Jun Wu, Fuwei Li
Journal of Catalysis 2017 Volume 355(Volume 355) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.jcat.2017.09.007
•Low-cost Co@N-doped graphene shells based catalysts were prepared.•Bifunctionality for catalytic hydrogenation and oxidative dehydrogenation.•Cobalt modified N-doped graphene shells act as active sites for O2 activation.•Nitrogen promoted Co nanoparticles act as active sites for H2 activation.Low-cost, active and stable catalysts, with a bifunctional capability if possible, are required to achieve the chemical transformations between saturated and unsaturated N-heterocycles. In this work, Co@N-doped graphene shells (Co@NGS) was used as a bifunctional catalyst with high activity and stability for the oxidative dehydrogenation (ODH) and hydrogenation (HYD) of quinolines. The excellent performance can be attributed to the synergetic effect of N-doped graphene, underlying Co nanoparticles, and the encapsulation structure in which carbon shells protect Co from leaching and aggregation. Poisoning tests with KSCN and spectroscopic analysis clearly unveil that the active sites for ODH and HYD are quite different: N-doped graphene shells modified by Co NPs via electron transfer serve as active sites for the O2 activation in ODH, while the underlying Co NPs promoted by N dopants favor the H2 activation in HYD. This finding challenges the previous concept of N-doped carbon sites as active sites for both ODH and HYD. The bifunctional property is due to the access of both N-doped graphene and Co sites to small molecules in our one-pot pyrolyzed Co@NGS catalysts.Download high-res image (99KB)Download full-size image
Co-reporter:Jun Wu, Guang Gao, Jinlei Li, Peng Sun, Xiangdong Long, Fuwei Li
Applied Catalysis B: Environmental 2017 Volume 203(Volume 203) pp:
Publication Date(Web):1 April 2017
DOI:10.1016/j.apcatb.2016.10.038
•Highly dispersed CuNi alloy nanoparticle supported catalysts are fabricated.•Selectivity-switchable conversion of furfural to THFA or FOL with CuNi alloy catalysts.•The CuNi alloy promoted by synergy shows excellent catalytic property and stability.•The structure-activity relationships in CuNi alloy catalysts are studied in detail.The development of efficient and environmental benign non-noble bimetallic nanocatalysts is highly desirable and attractive in the upgrading of biomass-derived platform compounds to high-valued chemicals. A series of highly dispersed and versatile CuxNiy (x/y = 7:1, 3:1, 1:1, 1:3, 1:7) alloy supported nanocatalysts derived from layer double hydroxides (LDHs) precursors were fabricated and used for the selective hydrogenation of furfural to tetrahydrofurfuryl alcohol (THFA) and furfuryl alcohol (FOL). It was found that the chemical composition, preparation method and especially the reduction temperature of LDHs precursors greatly affected the properties of the resultant CuxNiy/MgAlO catalysts. Systematic characterizations revealed that the reduction temperature of catalyst precursor was closely related to the dispersion and homogeneous composition of CuNi alloy nanoparticle as well as the surface basicity of catalysts, which played crucial roles in achieving excellent catalytic performances. The optimized CuNi/MgAlO and Cu1Ni3/MgAlO nanocatalysts showed high activity and selectivity for the hydrogenation of furfural to THFA in ethanol compared with the monometallic Ni and the CuNi supported catalysts prepared with other methods, such enhanced catalytic performance was investigated to be enabled by the synergistic effect within the CuNi alloy nanoparticles. Interestingly, our bimetallic nanocatalysts could also realize efficient production of FOL from the selective hydrogenation of furfural at its aldehyde group by simply changing the solvent to methanol. Moreover, the bimetallic nanocatalysts showed good recyclability in the liquid phase hydrogenation. Our efficient and versatile CuNi alloy nanocatalysts not only provide promising candidates for effective upgrading of furfural but also broaden the application of non-noble bimetallic nanocatalysts for hydrogenative transformations.Download high-res image (245KB)Download full-size image
Co-reporter:Jingjing Zhao, Pan Li, Xinjian Li, Chungu Xia and Fuwei Li
Chemical Communications 2016 vol. 52(Issue 18) pp:3661-3664
Publication Date(Web):01 Feb 2016
DOI:10.1039/C5CC09730D
A novel and direct approach to synthesize a series of phosphonate, azide and hydroxy functionalized chroman-4-ones has been developed. The cascade transformation appears to proceed through an intramolecular addition of an in situ generated acyl radical onto the alkene, followed by a selective nucleophilic radical–electrophilic radical cross coupling.
Co-reporter:Qi Xing, Hui Lv, Chungu Xia and Fuwei Li
Chemical Communications 2016 vol. 52(Issue 3) pp:489-492
Publication Date(Web):26 Oct 2015
DOI:10.1039/C5CC07390A
A simple iron-catalyzed aerobic oxidative C–C σ-bond cleavage of ketones has been developed. Readily available and environmentally benign air is used as the oxidant. This reaction avoids the use of noble metal catalysts or specialized oxidants, chemoselectively yielding carbon chain-shortened aldehydes, ketones and 1,2-dicarbonyl compounds without overoxidation.
Co-reporter:Hui Lv, Qi Xing, Chengtao Yue, Ziqiang Lei and Fuwei Li
Chemical Communications 2016 vol. 52(Issue 39) pp:6545-6548
Publication Date(Web):15 Apr 2016
DOI:10.1039/C6CC01234E
An unprecedented catalyst-free formylation of amines using CO2 and hydrosilanes was developed. The solvent plays a vital role in promoting the interaction of amines with hydrosilanes and subsequent CO2 insertion, thus facilitating the simultaneous activation of N–H and Si–H bonds. Based on relevant mechanistic studies, a plausible mechanism involving a silyl carbamate intermediate is proposed.
Co-reporter:Lijun Shi, Xiang Zhong, Houde She, Ziqiang Lei and Fuwei Li
Chemical Communications 2015 vol. 51(Issue 33) pp:7136-7139
Publication Date(Web):16 Mar 2015
DOI:10.1039/C5CC00249D
The Mn-catalyzed C–H alkenylation reactions of indole with terminal- and internal-alkynes have been developed. In the presence of a catalytic amount of acid, the procedure efficiently affords bis/trisubstituted indolyl-alkenes in a highly regio- and stereo-selective manner. Without the addition of acid, the reaction undergoes a [2+2+2] cyclization process to give carbazoles with release of hydrogen gas. Notably, the directing pyrimidyl group can be readily removed. Experimental studies reveal that the reaction is initiated by a C–H activation step and the acid is the selectivity controller via a hydrogen transfer process.
Co-reporter:Guodong Zhang;Rui Lang;Wenlong Wang;Hui Lv;Liyuan Zhao;Chungu Xia
Advanced Synthesis & Catalysis 2015 Volume 357( Issue 5) pp:917-922
Publication Date(Web):
DOI:10.1002/adsc.201401140
Co-reporter:Jinlei Li, Zelong Li, Jinhui Tong, Chungu Xia and Fuwei Li
RSC Advances 2015 vol. 5(Issue 86) pp:70010-70016
Publication Date(Web):06 Aug 2015
DOI:10.1039/C5RA10484J
Nitrogen-doped ordered mesoporous carbon spheres (N-OMCS) were fabricated by an efficient aqueous self-assembly process with F127 as a template, phenol resin and dicyandiamide (DCDA) as carbon and nitrogen sources respectively. It was found that the N-OMCS displayed the homogeneous nitrogen dispersion, well-defined monodispersed spherical morphology with ordered mesoporous structure as well as short channel. The prepared N-OMCS-1.5-900 showed good catalytic activity, excellent stability and resistance to methanol oxidation in oxygen reduction reaction (ORR). The significant electrocatalytic performance could be attributed to the formation of carbon spheres with ordered mesoporous structure and short channel, which not only facilitated the mass transfer, but also provided abundant active sites on the surface. In addition, the graphitic degree and the different nitrogen species of N-OMCS-1.5-900 also played an important role in ORR. The successful synthesis and application of N-OMCS could provide a feasible method for the fabrication of heteroatom-doped ordered mesoporous carbon nanospheres and may also boost the development of the efficient metal-free electrocatalysts.
Co-reporter:Jingjing Zhao, Pan Li, Chungu Xia and Fuwei Li
RSC Advances 2015 vol. 5(Issue 41) pp:32835-32838
Publication Date(Web):01 Apr 2015
DOI:10.1039/C5RA04632G
A direct and eco-friendly nitration methodology to synthesize 3-nitroquinoline N-oxides from quinoline N-oxides using tert-butyl nitrite as both the nitro source and oxidant has been developed. Although this reaction undergoes a free radical process, it exhibits high regioselectivity and can be smoothly scaled up to gram scale.
Co-reporter:Qi Xing ;Hui Lv;Dr. Chungu Xia;Dr. Fuwei Li
Chemistry - A European Journal 2015 Volume 21( Issue 23) pp:8591-8596
Publication Date(Web):
DOI:10.1002/chem.201500272
Abstract
A copper-catalyzed CC bond cleavage reaction of 1,3-dicarbonyl compounds with 2-iodoanilines was developed. In this process, the ortho effect played an important role in the reactivity and a new reaction pathway that involved a (2-aminophenyl)-bis-(1,3-dicarbonyl) copper species was clearly observed by a time-course HRMS analysis of the reaction mixture. Unlike the previous reports, both the nucleophilic and electrophilic parts of the 1,3-dicarbonyl compound were coupled with 2-iodoaniline by CC bond cleavage to form o-(N-acylamino)aryl ketones, which could be efficiently converted into multisubstituted indoles.
Co-reporter:Dr. Zelong Li;Dr. Guanglan Li; Luhua Jiang;Jinlei Li; Gongquan Sun; Chungu Xia; Fuwei Li
Angewandte Chemie International Edition 2015 Volume 54( Issue 5) pp:1494-1498
Publication Date(Web):
DOI:10.1002/anie.201409579
Abstract
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 Fe10@NOMC exhibits comparable catalytic activity but superior long-term stability to 20 wt % Pt/C for ORR with four-electron transfer pathway under alkaline conditions. Such outstanding catalytic performance is ascribed to the populated Fe (Fe3O4) 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.
Co-reporter:Jingjing Zhao;Pan Li;Dr. Chungu Xia;Dr. Fuwei Li
Chemistry - A European Journal 2015 Volume 21( Issue 46) pp:16383-16386
Publication Date(Web):
DOI:10.1002/chem.201503260
Abstract
A mild and convenient synthesis of carbazoles by TfOTMS (trimethylsilyl trifluoromethanesulfonate)-catalyzed ring-opening annulation of 2-amidodihydrofurans is presented with a high degree of chemoselectivity and regioselectivity. This procedure was also scaled up to a gram-scale synthesis. The reaction could involve an iminonium intermediate through a series of CO, CN bond cleavages, CC bond formations, and a 1,2-migration process.
Co-reporter:Jun Yi, Li Yang, Chungu Xia, and Fuwei Li
The Journal of Organic Chemistry 2015 Volume 80(Issue 12) pp:6213-6221
Publication Date(Web):May 18, 2015
DOI:10.1021/acs.joc.5b00669
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(sp2)–C(sp) bond.
Co-reporter:Wenlong Wang, Anmin Zheng, Peiqing Zhao, Chungu Xia, and Fuwei Li
ACS Catalysis 2014 Volume 4(Issue 1) pp:321
Publication Date(Web):December 11, 2013
DOI:10.1021/cs400983y
The synthetic control and functions of porous organic polymers (POPs) with N-heterocyclic carbene gold(I) (Au-NHC@POPs) are described in this article. A series of Au-NHC@POPs with tunable physical properties such as surface area and pore size distribution were first synthesized via Sonogashira chemistry by differing monomer strut lengths and concentration during polymerization; a controllable transition from nonporous to microporous and the coexistence of micro- and mesoporous structures in the framework were realized by varying the monomer concentration. To explain this phenomenon, we put forward a model assumption of a branch–branch cross effect. Additionally, Au-NHC@POPs1 was found to have superior catalytic activity in alkyne hydration reactions, and the catalyst could be used six times with a slight loss of activity.Keywords: alkyne hydration; cross-coupling; N-heterocyclic carbene; porous organic polymers; synthetic control
Co-reporter:Ying Yang, Guang Gao, Xin Zhang, and Fuwei Li
ACS Catalysis 2014 Volume 4(Issue 5) pp:1419
Publication Date(Web):March 25, 2014
DOI:10.1021/cs401030u
Bimetallic catalysts are of great importance due to their unique catalytic properties. However, their conventional synthesis requires tedious multistep procedures and prolonged synthetic time, and the resulting bimetallics usually disperse unevenly and show poor stability. It is challenging to develop a facile and step-economic synthetic methodology for highly efficient bimetallic catalysts. In this study, we report an elegant metal complex-involved multicomponent assembly route to highly efficient Ru–Ni bimetallics in ordered mesoporous carbons (OMC). The fabrication of composition-tuned Ru–Ni bimetallics in OMC (RuxNi1–x–OMC, x = 0.5–0.9) was facilely realized via in situ construction of CTAB-directed cubic Ia3d chitosan-ruthenium–nickel–silica mesophase before pyrolysis and silica removal. The resulting RuxNi1–x–OMC materials are in-depth characterized with X-ray diffraction, N2 adsorption–desorption, transmission electron microscopy, infrared spectrum, and X-ray absorption fine structure. This facile fabrication method renders homogeneously dispersed Ru–Ni bimetallics embedded in the mesoporous carbonaceous framework and creates a highly active and stable Ru0.9Ni0.1–OMC catalyst for the hydrogenation of levulinic acid (LA) to prepare γ-valerolactone (GVL), a biomass-derived platform molecule with wide application in the preparation of renewable chemicals and liquid transportation fuels. A high TOF (>2000 h–1) was obtained, and the Ru0.9Ni0.1–OMC catalyst could be used at least 15 times without obvious loss of its catalytic performance.Keywords: embedded bimetallics; high stability; levulinic acid hydrogenation; ordered mesoporous carbon; pyrolysis; self-assembly
Co-reporter:Peng Sun, Guang Gao, Zelun Zhao, Chungu Xia, and Fuwei Li
ACS Catalysis 2014 Volume 4(Issue 11) pp:4136
Publication Date(Web):October 13, 2014
DOI:10.1021/cs501409s
We herein report, for the first time, a bifunctional base-metal catalyst (Co@HZSM-5) that acts as an efficient alternative to noble-metal catalysts (e.g., Pt, Ru) for the conversion of levulinic acid into valeric biofuel under batch and fixed-bed reactor conditions. The cobalt nanoparticles were embedded in HZSM-5 crystals and catalyzed the sequential hydrogenations of the ketone and alkene functional groups; meanwhile, the acidic zeolite catalyzed the ring opening of the γ-valerolactone intermediate. Although base metals (e.g., Co) are abundant and inexpensive, their sintering and/or leaching under liquid-phase conditions always lead to the irreversible deactivation of the catalyst. In this system, the embedment structure stabilizes the nanoparticles, and Co@HZSM-5 could be used up to eight times. This work provides a practical clue toward the stabilization of base-metal catalysts and will inspire the development of large-scale biorefinery.Keywords: biofuel; cobalt; levulinic acid; stability; valerate esters
Co-reporter:Qi Xing, Pan Li, Hui Lv, Rui Lang, Chungu Xia and Fuwei Li
Chemical Communications 2014 vol. 50(Issue 81) pp:12181-12184
Publication Date(Web):21 Aug 2014
DOI:10.1039/C4CC05047A
A facile acid-catalyzed acylation of indoles with 1,3-dione as an eco-friendly acylating agent was developed. This protocol combines C–C bond cleavage and heterocyclic C–H bond functionalization to form new C–C bonds. Based on the detailed mechanistic studies, a credible mechanistic pathway was proposed.
Co-reporter:Jianming Liu, Xin Zhang, Lijun Shi, Muwen Liu, Yuanyuan Yue, Fuwei Li and Kelei Zhuo
Chemical Communications 2014 vol. 50(Issue 69) pp:9887-9890
Publication Date(Web):08 Jul 2014
DOI:10.1039/C4CC04377D
Facile synthesis of coumarin via the tandem reaction of salicylaldehyde with aryl-substituted 1,1-dibromo-1-alkene was developed. This new protocol proceeds smoothly under mild and transition-metal-free conditions, it allows rapid access to coumarins containing various heteroatoms that are more difficult to prepare by traditional methods. Based on the isolated intermediate of 4-(diethylamino)-3-phenylchroman-2-one and detailed mechanistic studies, a credible tandem pathway was proposed.
Co-reporter:Pan Li, Jingjing Zhao, Chungu Xia, and Fuwei Li
Organic Letters 2014 Volume 16(Issue 22) pp:5992-5995
Publication Date(Web):November 4, 2014
DOI:10.1021/ol503009f
An efficient manganese(III)-mediated oxidative coupling reaction between α-aryl enamides and 1,3-dicarbonyl compounds has been developed. A series of dihydrofurans and dicarbonyl enamides were synthesized in moderate to good yields. Moreover, these dihydrofurans could be readily transformed into the corresponding furans and pyrroles via the Paal–Knorr reaction.
Co-reporter:Jingjing Zhao, Pan Li, Chungu Xia and Fuwei Li
Chemical Communications 2014 vol. 50(Issue 36) pp:4751-4754
Publication Date(Web):18 Mar 2014
DOI:10.1039/C4CC01587H
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.
Co-reporter:Rui Lang, Chungu Xia and Fuwei Li
New Journal of Chemistry 2014 vol. 38(Issue 7) pp:2732-2738
Publication Date(Web):21 Feb 2014
DOI:10.1039/C4NJ00099D
The past decades have witnessed tremendous development in the field of carbonylative functionalization of aromatic compounds. In this context, various heterocycles could be directly utilized as simple starting materials to generate carbonyl group containing target molecules. This methodology has practical values, as the corresponding products could be used as useful building blocks in the synthesis of biologically active compounds. In this short review, we summarize the very recent development of this type of carbonylation reaction.
Co-reporter:Pan Li, Jingjing Zhao, Rui Lang, Chungu Xia, Fuwei Li
Tetrahedron Letters 2014 Volume 55(Issue 2) pp:390-393
Publication Date(Web):8 January 2014
DOI:10.1016/j.tetlet.2013.11.040
A copper-catalyzed synthesis of methyl esters from aromatic aldehydes in the presence of tert-butyl hydrogen peroxide (TBHP) was developed via a radical reaction mechanism. TBHP acts not only as an efficient oxidant, but also as a green methyl source in such transformation. Moreover, this method could also be efficiently extended to the methyl esterification of benzylic alcohols.
Co-reporter:Dr. Zelong Li;Dr. Jinlei Li;Dr. Jianhua Liu;Dr. Zelun Zhao;Dr. Chungu Xia;Dr. Fuwei Li
ChemCatChem 2014 Volume 6( Issue 5) pp:1333-1339
Publication Date(Web):
DOI:10.1002/cctc.201301037
Abstract
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 10 times without the loss of catalytic performance.
Co-reporter:Lijun Shi;Liqin Xue;Rui Lang;Dr. Chungu Xia ;Dr. Fuwei Li
ChemCatChem 2014 Volume 6( Issue 9) pp:2560-2566
Publication Date(Web):
DOI:10.1002/cctc.201402277
Abstract
The carbonylative domino synthesis of enaminones and pyrazoles has been performed with the NN bidentate palladium catalyst to achieve excellent selectivity. These results have confirmed that the carbonylative Sonogashira coupling of iodobenzenes with terminal alkynes is accompanied by the Michael addition of amines or phenylhydrazine in a one-pot method, which generates the desired products. This protocol demonstrates wide substrate tolerance, including hitherto unused aromatic amines, to yield the corresponding pure aromatic β-enaminones, which are subsequently converted into the 3-acylindole derivatives under mild conditions.
Co-reporter:Zelong Li, Jianhua Liu, Zhiwei Huang, Ying Yang, Chungu Xia, and Fuwei Li
ACS Catalysis 2013 Volume 3(Issue 5) pp:839
Publication Date(Web):March 19, 2013
DOI:10.1021/cs400077r
In this work, we report a novel and facile procedure for a one-pot preparation of palladium nanoparticle catalysts supported on porous N-doped carbon (Pd@CNT) by direct carbonization of palladium-N-heterocyclic carbene coordination polymer (P-Pd-NHC). This method could be conveniently extended to the synthesis of the Ni and alloy (PdxNiy) nanoparticle catalysts (Ni@CN800, PdxNiy@CN800). The treatment temperature played an important role on the growth and properties of the resultant M@CNT, wherein M@CN800 carbonized at 800 °C showed well-monodispersed metal nanoparticles (MNPs), graphene-like layers of the N-doped carbon supports, and strong interaction between MNPs and the support. Pd@CN800 displayed high efficiency and stable recyclability toward the domino carbonylative synthesis of pyrazole derivatives. Interestingly, its catalytic performance has been even higher than that of the representative PdCl2(PPh3)2 within six runs.Keywords: carbonylation; N-doped carbon; N-heterocyclic carbenes; nanoparticles; supported catalysts
Co-reporter:Zelong Li, Jianhua Liu, Chungu Xia, and Fuwei Li
ACS Catalysis 2013 Volume 3(Issue 11) pp:2440
Publication Date(Web):September 16, 2013
DOI:10.1021/cs400506q
N-functionalized ordered mesoporous carbons could be readily obtained by post-synthesis treatment with nitrogen containing molecules to achieve materials with a nitrogen loading as high as 8.6 wt % and well preserved mesopore structure. Using NH3 as nitrogen source dramatically increased the Brunauer–Emmett–Teller (BET) surface area and pore volume of the resultant hybrid material; however, N-doping with melamine as a source resulted in the contrary results. The N-doped carbons were used as supports to immobilize small-sized Pd nanoparticles (PdNPs), which provided a unique platform to investigate the influence of metal nanoparticle size, mesostructural properties, and N-functionalized supports on the selective hydrogenation of phenol to cyclohexanone, an important intermediate in the production of nylon 6 and nylon 66 in the chemical industry. The catalyst with ultrasmall (about 1.2 nm) PdNPs gave the best reaction activity and selectivity under mild conditions. In addition, the present multifunctional catalyst demonstrated excellent catalytic stability and could be used 6 times without loss of product yields. This outstanding catalytic performance could be attributed to the synergetic effects of mesoporous structure, N-functionalized supports, and the stabilized ultrasmall PdNPs. This work might open new avenues for the development of functionalized catalysts with supported ultrasmall metal nanoparticles and hybrid porous support as well as their clean catalyses.Keywords: heterogeneous catalysis; hydrogenation; N-doped ordered mesoporous carbon; ultrasmall Pd nanoparticles
Co-reporter:Wenlong Wang, Guodong Zhang, Rui Lang, Chungu Xia and Fuwei Li
Green Chemistry 2013 vol. 15(Issue 3) pp:635-640
Publication Date(Web):10 Jan 2013
DOI:10.1039/C3GC36830K
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.
Co-reporter:Dr. Peng Sun;Xiangdong Long;Hao He;Dr. Chungu Xia;Dr. Fuwei Li
ChemSusChem 2013 Volume 6( Issue 11) pp:
Publication Date(Web):
DOI:10.1002/cssc.201301044
Co-reporter:Dr. Peng Sun;Xiangdong Long;Hao He;Dr. Chungu Xia;Dr. Fuwei Li
ChemSusChem 2013 Volume 6( Issue 11) pp:2190-2197
Publication Date(Web):
DOI:10.1002/cssc.201300701
Abstract
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 50 % yield of isosorbide with almost 100 % cellulose conversion can be obtained in 1 h. 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.
Co-reporter:Rui Lang, Lijun Shi, Dengfeng Li, Chungu Xia, and Fuwei Li
Organic Letters 2012 Volume 14(Issue 16) pp:4130-4133
Publication Date(Web):July 27, 2012
DOI:10.1021/ol3017726
A novel strategy involving a first oxidative iodination and subsequent Pd0-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.
Co-reporter:Qi Xing, Lijun Shi, Rui Lang, Chungu Xia and Fuwei Li
Chemical Communications 2012 vol. 48(Issue 89) pp:11023-11025
Publication Date(Web):25 Sep 2012
DOI:10.1039/C2CC36341K
A novel and efficient double-carbonylation of indoles with primary or secondary amines to yield indole-3-α-ketoamides has been developed and bioactive molecules could be one-pot synthesized using the current methodology, which could also be selectively switched to mono-carbonylation to afford indole-3-amides only by a slight modification of reaction conditions.
Co-reporter:Chaodong Hou, Yunlai Ren, Rui Lang, Xiaoxue Hu, Chungu Xia and Fuwei Li
Chemical Communications 2012 vol. 48(Issue 42) pp:5181-5183
Publication Date(Web):05 Apr 2012
DOI:10.1039/C2CC30429E
The first Pd-catalyzed direct phosphonation of azoles with dialkyl phosphites has been achieved without addition of base or acid. This method involves the oxidative cleavage of C–H and P(O)–H bonds and represents an atom-efficiency alternative to the classical phosphonation of Ar–X. A PdII/PdIV mechanism has been studied and proposed.
Co-reporter:Wenlong Wang, Junliang Wu, Chungu Xia and Fuwei Li
Green Chemistry 2011 vol. 13(Issue 12) pp:3440-3445
Publication Date(Web):20 Oct 2011
DOI:10.1039/C1GC15871F
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.
Co-reporter:Rui Lang, Junliang Wu, Lijun Shi, Chungu Xia and Fuwei Li
Chemical Communications 2011 vol. 47(Issue 46) pp:12553-12555
Publication Date(Web):26 Oct 2011
DOI:10.1039/C1CC15143F
Rh-catalyzed C–H carbonylation of indoles under 1 atm of CO has been achieved. Various substituted indoles and indole with free N–H could be carboxylated with linear- and/or cyclic-alcohol to give the desired indole-3-carboxylates with up to 92% yield. A mechanism involving RhIII initiated C–H metallation is proposed.
Co-reporter:Liqin Xue, Lijun Shi, Yuan Han, Chungu Xia, Han Vinh Huynh and Fuwei Li
Dalton Transactions 2011 vol. 40(Issue 29) pp:7632-7638
Publication Date(Web):15 Jun 2011
DOI:10.1039/C1DT10433K
A series of carbene complexes [PdBr2(iPr2-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.
Co-reporter:Li Zhang, Junliang Wu, Lijun Shi, Chungu Xia, Fuwei Li
Tetrahedron Letters 2011 Volume 52(Issue 30) pp:3897-3901
Publication Date(Web):27 July 2011
DOI:10.1016/j.tetlet.2011.05.079
An imidazolium chloride tagged palladium(II) complex has been conveniently prepared and structurally analyzed. It is active toward cross-coupling of arylboronic acid with aryl halide and benzoyl chloride, giving moderate to high yield of the desired biaryls and aryl ketones, respectively. The present phosphine-free (N–N)Pd(II) complex could be efficiently recycled at least four times with minor decrease of activity in the aqueous Suzuki–Miyaura coupling reaction.
Co-reporter:Peng Sun, Guang Gao, Zelun Zhao, Chungu Xia, Fuwei Li
Applied Catalysis B: Environmental (15 July 2016) Volume 189() pp:19-25
Publication Date(Web):15 July 2016
DOI:10.1016/j.apcatb.2016.02.026
Co-reporter:Rui Lang, Junliang Wu, Lijun Shi, Chungu Xia and Fuwei Li
Chemical Communications 2011 - vol. 47(Issue 46) pp:NaN12555-12555
Publication Date(Web):2011/10/26
DOI:10.1039/C1CC15143F
Rh-catalyzed C–H carbonylation of indoles under 1 atm of CO has been achieved. Various substituted indoles and indole with free N–H could be carboxylated with linear- and/or cyclic-alcohol to give the desired indole-3-carboxylates with up to 92% yield. A mechanism involving RhIII initiated C–H metallation is proposed.
Co-reporter:Qi Xing, Lijun Shi, Rui Lang, Chungu Xia and Fuwei Li
Chemical Communications 2012 - vol. 48(Issue 89) pp:NaN11025-11025
Publication Date(Web):2012/09/25
DOI:10.1039/C2CC36341K
A novel and efficient double-carbonylation of indoles with primary or secondary amines to yield indole-3-α-ketoamides has been developed and bioactive molecules could be one-pot synthesized using the current methodology, which could also be selectively switched to mono-carbonylation to afford indole-3-amides only by a slight modification of reaction conditions.
Co-reporter:Jianming Liu, Xin Zhang, Lijun Shi, Muwen Liu, Yuanyuan Yue, Fuwei Li and Kelei Zhuo
Chemical Communications 2014 - vol. 50(Issue 69) pp:NaN9890-9890
Publication Date(Web):2014/07/08
DOI:10.1039/C4CC04377D
Facile synthesis of coumarin via the tandem reaction of salicylaldehyde with aryl-substituted 1,1-dibromo-1-alkene was developed. This new protocol proceeds smoothly under mild and transition-metal-free conditions, it allows rapid access to coumarins containing various heteroatoms that are more difficult to prepare by traditional methods. Based on the isolated intermediate of 4-(diethylamino)-3-phenylchroman-2-one and detailed mechanistic studies, a credible tandem pathway was proposed.
Co-reporter:Jingjing Zhao, Pan Li, Chungu Xia and Fuwei Li
Chemical Communications 2014 - vol. 50(Issue 36) pp:NaN4754-4754
Publication Date(Web):2014/03/18
DOI:10.1039/C4CC01587H
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.
Co-reporter:Lijun Shi, Xiang Zhong, Houde She, Ziqiang Lei and Fuwei Li
Chemical Communications 2015 - vol. 51(Issue 33) pp:NaN7139-7139
Publication Date(Web):2015/03/16
DOI:10.1039/C5CC00249D
The Mn-catalyzed C–H alkenylation reactions of indole with terminal- and internal-alkynes have been developed. In the presence of a catalytic amount of acid, the procedure efficiently affords bis/trisubstituted indolyl-alkenes in a highly regio- and stereo-selective manner. Without the addition of acid, the reaction undergoes a [2+2+2] cyclization process to give carbazoles with release of hydrogen gas. Notably, the directing pyrimidyl group can be readily removed. Experimental studies reveal that the reaction is initiated by a C–H activation step and the acid is the selectivity controller via a hydrogen transfer process.
Co-reporter:Hui Lv, Qi Xing, Chengtao Yue, Ziqiang Lei and Fuwei Li
Chemical Communications 2016 - vol. 52(Issue 39) pp:NaN6548-6548
Publication Date(Web):2016/04/15
DOI:10.1039/C6CC01234E
An unprecedented catalyst-free formylation of amines using CO2 and hydrosilanes was developed. The solvent plays a vital role in promoting the interaction of amines with hydrosilanes and subsequent CO2 insertion, thus facilitating the simultaneous activation of N–H and Si–H bonds. Based on relevant mechanistic studies, a plausible mechanism involving a silyl carbamate intermediate is proposed.
Co-reporter:Qi Xing, Pan Li, Hui Lv, Rui Lang, Chungu Xia and Fuwei Li
Chemical Communications 2014 - vol. 50(Issue 81) pp:NaN12184-12184
Publication Date(Web):2014/08/21
DOI:10.1039/C4CC05047A
A facile acid-catalyzed acylation of indoles with 1,3-dione as an eco-friendly acylating agent was developed. This protocol combines C–C bond cleavage and heterocyclic C–H bond functionalization to form new C–C bonds. Based on the detailed mechanistic studies, a credible mechanistic pathway was proposed.
Co-reporter:Jingjing Zhao, Pan Li, Xinjian Li, Chungu Xia and Fuwei Li
Chemical Communications 2016 - vol. 52(Issue 18) pp:NaN3664-3664
Publication Date(Web):2016/02/01
DOI:10.1039/C5CC09730D
A novel and direct approach to synthesize a series of phosphonate, azide and hydroxy functionalized chroman-4-ones has been developed. The cascade transformation appears to proceed through an intramolecular addition of an in situ generated acyl radical onto the alkene, followed by a selective nucleophilic radical–electrophilic radical cross coupling.
Co-reporter:Pan Li, Jingjing Zhao, Chungu Xia and Fuwei Li
Inorganic Chemistry Frontiers 2015 - vol. 2(Issue 10) pp:NaN1317-1317
Publication Date(Web):2015/07/20
DOI:10.1039/C5QO00204D
Although radical oxidative coupling provides a powerful C–H functionalization tool, the selective coupling of an electrophilic radical with a heterocyclic electron-deficient C2 site is still a seemingly impossible challenge. In this work, an efficient oxidative C2–H azidation of quinoline N-oxides with TMSN3 has been developed, proceeding at room temperature within 10 min. Based on control experiments and detailed EPR studies, the reaction appears to involve a novel carbene-stabilized N–O radical intermediate, which undergoes a single electron transfer to TMSN3 to give the C2-azidation product. Moreover, this procedure could be smoothly scaled up to gram-synthesis and the products could be converted into other functional heterocycles.
Co-reporter:Chaodong Hou, Yunlai Ren, Rui Lang, Xiaoxue Hu, Chungu Xia and Fuwei Li
Chemical Communications 2012 - vol. 48(Issue 42) pp:NaN5183-5183
Publication Date(Web):2012/04/05
DOI:10.1039/C2CC30429E
The first Pd-catalyzed direct phosphonation of azoles with dialkyl phosphites has been achieved without addition of base or acid. This method involves the oxidative cleavage of C–H and P(O)–H bonds and represents an atom-efficiency alternative to the classical phosphonation of Ar–X. A PdII/PdIV mechanism has been studied and proposed.
Co-reporter:Liqin Xue, Lijun Shi, Yuan Han, Chungu Xia, Han Vinh Huynh and Fuwei Li
Dalton Transactions 2011 - vol. 40(Issue 29) pp:NaN7638-7638
Publication Date(Web):2011/06/15
DOI:10.1039/C1DT10433K
A series of carbene complexes [PdBr2(iPr2-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.
Co-reporter:Qi Xing, Hui Lv, Chungu Xia and Fuwei Li
Chemical Communications 2016 - vol. 52(Issue 3) pp:NaN492-492
Publication Date(Web):2015/10/26
DOI:10.1039/C5CC07390A
A simple iron-catalyzed aerobic oxidative C–C σ-bond cleavage of ketones has been developed. Readily available and environmentally benign air is used as the oxidant. This reaction avoids the use of noble metal catalysts or specialized oxidants, chemoselectively yielding carbon chain-shortened aldehydes, ketones and 1,2-dicarbonyl compounds without overoxidation.
Co-reporter:Qi Xing, Hui Lv, Chungu Xia and Fuwei Li
Chemical Communications 2017 - vol. 53(Issue 51) pp:NaN6917-6917
Publication Date(Web):2017/06/07
DOI:10.1039/C7CC03274A
An efficient palladium-catalyzed oxidative aminocarbonylation of azoles has been developed. This system allows for intermolecular carbonylative cross-coupling of aromatic C(sp2)–H bonds with simple amines, which has often been asked for, but has not been realized so far. It provides a straightforward approach to a variety of azol-2-amides.