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Current Organocatalysis

Editor-in-Chief

ISSN (Print): 2213-3372
ISSN (Online): 2213-3380

Research Article

High Catalytic Activity of Pd Nanoparticles Synthesized from Green Alga Chlorella vulgaris in Buchwald-hartwig Synthesis of N-Aryl Piperazines

Author(s): Vaibhav Mishra, Anju Arya and Tejpal Singh Chundawat*

Volume 7, Issue 1, 2020

Page: [23 - 33] Pages: 11

DOI: 10.2174/2213337206666190515091945

Abstract

Background: The N-aryl piperazines are an important component of many drug products used for the treatment of malaria, depression, anxiety and Parkinson diseases. Buchwald-Hartwig amination is the latest and well-known reaction for Pd catalyzed direct synthesis of N-aryl piperazine from aryl halides. Although several Pd-ligand systems have already been discovered for this conversion, Pd nanoparticles are recently being used for this useful coupling reaction due to their recyclability and durability. Metal nanoparticles show enhanced catalytic activity compared to their bulk counterparts due to increased surface area at the edges and corners. The use of green algal extract in place of chemical ligands makes this process more environment-friendly and cost-effective. In this research, Pd nanoparticles synthesized using green alga C. Vulgaris were utilized as an alternative approach for the coupling reaction during the preparation of N-aryl piperazines.

Methods: Synthesized Pd nanoparticles from C. Vulgaris were characterized by FTIR, SEM and XRD techniques. The catalytic activity of the synthesized nanoparticles was monitored for the synthesis of N-aryl piperazines by Buchwald-Hartwig reaction. The synthesized N-aryl piperazines were characterized by NMR, FTIR and mass analysis.

Results: A very good catalytic activity of the synthesized Pd nanoparticles from green alga Chlorella vulgaris extract was observed. The green alga not only reduces the size of the Pd metal to nanoparticles but also acts as a green ligand for reduction of Pd(II) to Pd(0) during nanoparticle synthesis. Using this Pd nanoparticles-green ligand system, several N-aryl piperazines were synthesized in good to excellent yields. Reaction conditions for better conversion were optimized. The comparative advantage of the catalytic system with recently published works on Buchwald-Hartwig C-N coupling reaction is given. Recyclability and durability of the catalyst were explored and the results were found to be promising. A plausible mechanism of Pd nanoparticle catalyzed reaction is also proposed.

Conclusion: Catalytic activity of the Pd nanoparticle synthesized from Chlorella vulagris in the synthesis of N-aryl piperazines by Buchwald-Hartwig reaction is reported first time to the best of our knowledge and understanding. The green approach of Pd catalyst to facilitate the reaction and its environmental impact is the main characteristic of the process.

Keywords: Buchwald-Hartwig reaction, C-N bond formation, catalysis, green alga, N-aryl piperazine, Pd nanoparticle.

Graphical Abstract
[1]
Horton, D.A.; Bourne, G.T.; Smythe, M.L. The combinatorial synthesis of bicyclic privileged structures or privileged substructures. Chem. Rev., 2003, 103(3), 893-930.
[http://dx.doi.org/10.1021/cr020033s] [PMID: 12630855]
[2]
(a) Berardi, F.; Abate, C.; Ferorelli, S.; de Robertis, A.F.; Leopoldo, M.; Colabufo, N.A.; Niso, M.; Perrone, R. Novel 4-(4-aryl)cyclohexyl-1-(2-pyridyl)piperazines as Δ(8)-Δ(7) sterol isomerase (emopamil binding protein) selective ligands with antiproliferative activity. J. Med. Chem., 2008, 51(23), 7523-7531.
[http://dx.doi.org/10.1021/jm800965b] [PMID: 19053780]
(b) Mao, Z.W.; Zheng, X.; Lin, Y.P.; Hu, C.Y.; Wang, X.L.; Wan, C.P.; Rao, G.X. Design, synthesis and anticancer activity of novel hybrid compounds between benzofuran and N-aryl piperazine. Bioorg. Med. Chem. Lett., 2016, 26(15), 3421-3424.
[http://dx.doi.org/10.1016/j.bmcl.2016.06.055] [PMID: 27371110]
(c) Chen, H.; Xu, F.; Liang, X.; Xu, B.; Yang, Z.; He, X.; Huang, B.; Yuan, M. Design and synthesis of novel arylpiperazine derivatives on human prostate cancer cells. Bioorg. Med. Chem. Lett., 2015, 25, 285-287.
[http://dx.doi.org/10.1016/j.bmcl.2014.11.049] [PMID: 25488843]
(d) Mao, Z.; Zheng, X.; Qi, Y.; Zhang, M.; Huang, Y.; Wan, C.; Rao, G. Synthesis and biological evaluation of novel hybrid compounds between chalcone and piperazine as potential antitumor agents. RSC Adv, 2016, 6, 7723-7727.
[http://dx.doi.org/10.1039/C5RA20197G]
[3]
Cappelli, A.; Anzini, M.; Vomero, S.; Mennuni, L.; Makovec, F.; Doucet, E.; Hamon, M.; Bruni, G.; Romeo, M.R.; Menziani, M.C.; De Benedetti, P.G.; Langer, T. Novel potent and selective central 5-HT3 receptor ligands provided with different intrinsic efficacy. 1. Mapping the central 5-HT3 receptor binding site by arylpiperazine derivatives. J. Med. Chem., 1998, 41(5), 728-741.
[http://dx.doi.org/10.1021/jm970645i] [PMID: 9513601]
[4]
Romero, D.L.; Morge, R.A.; Genin, M.J.; Biles, C.; Busso, M.; Resnick, L.; Althaus, I.W.; Reusser, F.; Thomas, R.C.; Tarpley, W.G. Bis(heteroaryl)piperazine(BHAP) reverse transcriptase inhibitors:structure-activity relationships of novel substituted indole analogs and the identification of 1-[5-methanesulfonamido-1Hindol-2-yl)carbonyl-4-[3-[(1-methylethyl)amino]pyridinyl]piperazine(U-90152S),a second generation clinical candidate. J. Med. Chem., 1993, 36, 1505-1508.
[http://dx.doi.org/10.1021/jm00062a027] [PMID: 7684450]
[5]
Mendoza, A.; Pérez-Silanes, S.; Quiliano, M.; Pabón, A.; Galiano, S.; González, G.; Garavito, G.; Zimic, M.; Vaisberg, A.; Aldana, I.; Monge, A.; Deharo, E. Aryl piperazine and pyrrolidine as antimalarial agents. Synthesis and investigation of structure-activity relationships. Exp. Parasitol., 2011, 128(2), 97-103.
[http://dx.doi.org/10.1016/j.exppara.2011.02.025] [PMID: 21354139]
[6]
Koller, W.C.; Fields, J.Z.; Gordon, J.H.; Perlow, M.J. Evaluation of ciladopa hydrochloride as a potential anti-Parkinson drug. Neuropharmacology, 1986, 25(9), 973-979.
[http://dx.doi.org/10.1016/0028-3908(86)90190-5] [PMID: 3774130]
[7]
Loane, C.; Politis, M. Buspirone: what is it all about? Brain Res., 2012, 1461, 111-118.
[http://dx.doi.org/10.1016/j.brainres.2012.04.032] [PMID: 22608068]
[8]
Audinot, V.; Newman-Tancredi, A.; Gobert, A.; Rivet, J.M.; Brocco, M.; Lejeune, F.; Gluck, L.; Desposte, I.; Bervoets, K.; Dekeyne, A.; Millan, M.J. A comparative in vitro and in vivo pharmacological characterization of the novel dopamine D3 receptor antagonists (+)-S 14297, nafadotride, GR 103,691 and U 99194. J. Pharmacol. Exp. Ther., 1998, 287(1), 187-197.
[PMID: 9765337]
[9]
(a) Sokoloff, P.; Le Foll, B.; Perachon, S.; Bordet, R.; Ridray, S.; Schwartz, J.C. The dopamine D3 receptor and drug addiction. Neurotox. Res., 2001, 3(5), 433-441.
[http://dx.doi.org/10.1007/BF03033202] [PMID: 14715457]
(b) Pilla, M.; Perachon, S.; Sautel, F.; Garrido, F.; Mann, A.; Wermuth, C.G.; Schwartz, J.C.; Everitt, B.J.; Sokoloff, P. Selective inhibition of cocaine-seeking behaviour by a partial dopamine D3 receptor agonist. Nature, 1999, 400(6742), 371-375.
[http://dx.doi.org/10.1038/22560] [PMID: 10432116]
(c) Khaled, M.A.T.M.; Farid Araki, K.; Li, B.; Coen, K.M.; Marinelli, P.W.; Varga, J.; Gaál, J.; Le Foll, B. The selective dopamine D3 receptor antagonist SB 277011-A, but not the partial agonist BP 897, blocks cue-induced reinstatement of nicotine-seeking. Int. J. Neuropsychopharmacol., 2010, 13(2), 181-190.
[http://dx.doi.org/10.1017/S1461145709991064] [PMID: 19995481]
(d) Grundt, P.; Carlson, E.E.; Cao, J.; Bennet, C.J.; McElveen, E.; Taylor, M.; Luedtke, R.R.; Newman, A.H. Novel heterocyclic trans olefin analogues of N-4-[4[(2,3-dichlorophenyl)piperazine-1-yl]butyl arylcarboxamides as selective probes with high affinity for the dopamine receptor. J. Med. Chem., 2005, 48, 839-848.
[http://dx.doi.org/10.1021/jm049465g] [PMID: 15689168]
(e) Garcia-Ladona, F.J.; Cox, B.F. BP 897, a selective dopamine D3 receptor ligand with therapeutic potential for the treatment of cocaine-addiction. CNS Drug Rev., 2003, 9(2), 141-158.
[http://dx.doi.org/10.1111/j.1527-3458.2003.tb00246.x] [PMID: 12847556]
[10]
Nilsson, J.W.; Thorstensson, F.; Kvarnström, I.; Oprea, T.; Samuelsson, B.; Nilsson, I. Solid-phase synthesis of libraries generated from a 4-phenyl-2-carboxy-piperazine scaffold. J. Comb. Chem., 2001, 3(6), 546-553.
[http://dx.doi.org/10.1021/cc010013o] [PMID: 11703150]
[11]
Mishra, V.; Chundawat, T.S. Pd catalyzed N1/N4 arylation of piperazine for synthesis of drugs, biological and pharmaceutical targets: An overview of buchwald hartwig amination reaction of piperazine in drug synthesis. Curr. Org. Synth., 2018, 15(2), 208-220.
[http://dx.doi.org/10.2174/1570179415666171206151603]
[12]
Scott, D.A.; Dakin, L.A.; Daly, K.; Del Valle, D.J.; Diebold, R.B.; Drew, L.; Ezhuthachan, J.; Gero, T.W.; Ogoe, C.A.; Omer, C.A.; Redmond, S.P.; Repik, G.; Thakur, K.; Ye, Q.; Zheng, X. Mitigation of cardiovascular toxicity in a series of CSF-1R inhibitors, and the identification of AZD7507. Bioorg. Med. Chem. Lett., 2013, 23(16), 4591-4596.
[http://dx.doi.org/10.1016/j.bmcl.2013.06.031] [PMID: 23842474]
[13]
Ryu, J.H.; Kim, S.; Lee, J.A.; Han, H.Y.; Son, H.J.; Lee, H.J.; Kim, Y.H.; Kim, J.S.; Park, H.G. Synthesis and optimization of picolinamide derivatives as a novel class of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitors. Bioorg. Med. Chem. Lett., 2015, 25(8), 1679-1683.
[http://dx.doi.org/10.1016/j.bmcl.2015.03.003] [PMID: 25800116]
[14]
Krogsgaard-Larsen, N.; Jensen, A.A.; Schrøder, T.J.; Christoffersen, C.T.; Kehler, J. Novel aza-analogous ergoline derived scaffolds as potent serotonin 5-HT6 and dopamine D2 receptor ligands. J. Med. Chem., 2014, 57(13), 5823-5828.
[http://dx.doi.org/10.1021/jm5003759] [PMID: 24878269]
[15]
Flanagan, J.U.; Atwell, G.J.; Heinrich, D.M.; Brooke, D.G.; Silva, S.; Rigoreau, L.J.M.; Trivier, E.; Turnbull, A.P.; Raynham, T.; Jamieson, S.M.F.; Denny, W.A. Morpholylureas are a new class of potent and selective inhibitors of the type 5 17-β-hydroxysteroid dehydrogenase (AKR1C3). Bioorg. Med. Chem., 2014, 22(3), 967-977.
[http://dx.doi.org/10.1016/j.bmc.2013.12.050] [PMID: 24411201]
[16]
Lynch, S.M.; Tafesse, L.; Carlin, K.; Ghatak, P.; Shao, B.; Abdelhamid, H.; Kyle, D.J. N-Aryl azacycles as novel sodium channel blockers. Bioorg. Med. Chem. Lett., 2015, 25(1), 48-52.
[http://dx.doi.org/10.1016/j.bmcl.2014.11.023] [PMID: 25435147]
[17]
Bourbeau, M.P.; Ashton, K.S.; Yan, J.; St Jean, D.J., Jr Nonracemic synthesis of GK-GKRP disruptor AMG-3969. J. Org. Chem., 2014, 79(8), 3684-3687.
[http://dx.doi.org/10.1021/jo500336e] [PMID: 24678849]
[18]
Reilly, S.W.; Mach, R.H. Pd-catalyzed synthesis of piperazine scaffolds under aerobic and solvent free conditions. Org. Lett., 2016, 18(20), 5272-5275.
[http://dx.doi.org/10.1021/acs.orglett.6b02591] [PMID: 27736075]
[19]
Deeks, E.D. Venetoclax: first global approval. Drugs, 2016, 76(9), 979-987.
[http://dx.doi.org/10.1007/s40265-016-0596-x] [PMID: 27260335]
[20]
Itchaki, G.; Brown, J.R. The potential of venetoclax (ABT-199) in chronic lymphocytic leukemia. Ther. Adv. Hematol., 2016, 7(5), 270-287.
[http://dx.doi.org/10.1177/2040620716655350] [PMID: 27695617]
[21]
Vincent, S.C.; Alan, C.; Christesen, T.; Grieme, A.; Yi-Yin, K.; Mathew, M.M.; Yu-Ming, M.; Pu, W. Process for the preparation of an apoptosis-inducing agent. U.S. Patent 0,183,783 2015.
[22]
Koichi, S.; Naoto, U.; Masahiro, S.; Shigeo, F.; Shin, O. Method for producing benzo[b]thiophene compound. U.S. Patent 9,2016,169 2015.
[23]
Flick, A.C.; Ding, H.X.; Leverett, C.A.; Kyne, R.E., Jr; Liu, K.K.; Fink, S.J.; O’Donnell, C.J. Synthetic approaches to the 2014 new drugs. Bioorg. Med. Chem., 2016, 24(9), 1937-1980.
[http://dx.doi.org/10.1016/j.bmc.2016.03.004] [PMID: 27020685]
[24]
Yildiz, Y.; Erken, E.; Pamuk, H.; Sert, H.; Sen, F. Monodisperse Pt nanoparticles assembled on reduced graphene oxide: highly efficient and reusable catalyst for methanol oxidation and dehydrocoupling of dimethyl borane (DMAB). J. Nanosci. Nanotechnol., 2016, 16(6), 5951-5958.
[http://dx.doi.org/10.1166/jnn.2016.11710] [PMID: 27427656]
[25]
Erken, E.; Yildi, Y.; Kilbas, B.; Fatih, S. Synthesis and characterization of nearly monodisperse Pt nanoparticles for C1-C3 alcohol oxidation and dehydrogenation of DMAB. J. Nanosci. Nanotechnol., 2016, 16(6), 15944-15950.
[http://dx.doi.org/10.1166/jnn.2016.11683] [PMID: 27427655]
[26]
Fatih, S.; Gulsun, G.; Selda, S. High performance Pt nanoparticles prepared by new surfactants for C1 to C3 alcohol oxidation reactions. J. Nanopart. Res., 2013, 15(10), 1979.
[http://dx.doi.org/10.1007/s11051-013-1979-5]
[27]
Fatih, S.; Gulsun, G. Pt nanoparticles synthesized with new surfactants: improvement in C1-C3 alcohol oxidation catalytic activity. J. Appl. Electrochem., 2014, 44(1), 199-207.
[http://dx.doi.org/10.1007/s10800-013-0631-5]
[28]
Ozlem, K.; Yunus, Y.; Handan, P.; Sinan, E.; Zeynep, D.; Fatih, S. Enhanced electrocatalytic activity and durability of monodisperse Pt@PPY-PANI nanocomposites as a novel catalyst for the electro oxidation of methano. RSC Adv, 2016, 6(56), 50851-50857.
[http://dx.doi.org/10.1039/C6RA06210E]
[29]
Yunus, Y.; Sultan, K.; Betul, S.; Aysun, S.; Suleyman, A. fatih, S. Different ligand based monodispersed Pt nanoparticles decorated with rGO as highly active and reusable catalysts for the methanol oxidation. Int. J. Hyd. Eng., 2017, 42(18), 13061-13069.
[http://dx.doi.org/10.1016/j.ijhydene.2017.03.230]
[30]
Betul, S.; Sultan, K.; Enes, D.; Suleyman, A.; Fatih, S. Polymer graphene hybrid decorated Pt nanoparticles as highly efficient and reusable catalyst for the dehydrogenation of DMAB at room temperature. Int. J. Hyd. Eng., 2017, 42(36), 23284-23291.
[http://dx.doi.org/10.1016/j.ijhydene.2017.05.112]
[31]
Betul, S.; Sultan, K.; Enes, D. Suleyman, A.; Fatih, S. Highly monodisperse RuCo nanoparticles decorated on functionalized mutiwalled carbon nanotube with the highest observed catalytic activity in the dehydrogenation of DMAB. Int. J. Hyd. Eng., 2017, 42(36), 23292-23298.
[http://dx.doi.org/10.1016/j.ijhydene.2017.06.032]
[32]
Yunus, Y.; Tugba, O.; Betul, S.; Bahdisen, G.; Sultan, K.; Aysun, S.; Enes, D.; Zeynep, D.; Hakan, S.; Fatih, S. Highly monodisperse Pt/Rh nanoparticles confined in the graphene oxide for highly efficient and reusable sorbents for methylene blue removal from aqueous solutions. ChemistrySelect, 2017, 2(2), 697-701.
[http://dx.doi.org/10.1002/slct.201601608]
[33]
Deplanche, K.; Bennett, J.A.; Mikheenko, I.P.; Omajali, J.; Wells, A.S.; Meadows, R.E.; Wood, J.; Macaslie, L.E. Catalytic activity of biomass-supported Pd nanoparticles: Influenece of the biological component in catalytic efficacy and potential application in green synthesis of fine chemicals and pharmaceuticals. J. Mol. Catal., B Enzym., 2014, 147, 651-665.
[http://dx.doi.org/10.1016/j.apcatb.2013.09.045]
[34]
Bej, A.; Ghosh, K.; Sarkar, A.; Knight, D.W. Palladium nanoparticles in the catalysis of coupling reactions. RSC Adv, 2016, 6, 11446-11453.
[http://dx.doi.org/10.1039/C5RA26304B]
[35]
Nasrollahzadeh, M.; Sajadi, S.M.; Maham, M. Green synthesis of palladium nanoparticles using Hippphae rhamnoides linn leaf extract and their catalytic activity for the suzuki-miyaura coupling in water. J. Mol. Catal. Chem., 2015, 396, 297-303.
[http://dx.doi.org/10.1016/j.molcata.2014.10.019]
[36]
Goksu, H.; Nursefa, Z.; Arife, K.; Fatih, S. Highly active and reusable Pd/AlO(OH) nanoparticles for the suzuki cross coupling reaction. Curr. Organocatal., 2018, 5, 34-41.
[http://dx.doi.org/10.2174/2213337205666180614114550]
[37]
Biscoe, M.R.; Fors, B.P.; Buchwald, S.L.J. A new class of easily activated palladium precatalysts for facile C-N cross-coupling reactions and the low temperature oxidative addition of aryl chlorides. J. Am. Chem. Soc., 2008, 130(21), 6686-6687.
[http://dx.doi.org/10.1021/ja801137k] [PMID: 18447360]
[38]
Lawler, C.P.; Prioleau, C.; Lewis, M.M.; Mak, C.; Jiang, D.; Schetz, J.A.; Gonzalez, A.M.; Sibley, D.R.; Mailman, R.B. Interactions of the novel antipsychotic aripiprazole (OPC-14597) with dopamine and serotonin receptor subtypes. Neuropsychopharmacology, 1999, 20(6), 612-627.
[http://dx.doi.org/10.1016/S0893-133X(98)00099-2] [PMID: 10327430]
[39]
Chen, Y.L.; Fang, K.C.; Sheu, J.Y.; Hsu, S.L.; Tzeng, C.C. Synthesis and antibacterial evaluation of certain quinolone derivatives. J. Med. Chem., 2001, 44(14), 2374-2377.
[http://dx.doi.org/10.1021/jm0100335] [PMID: 11428933]
[40]
Goksu, H.; Yunus, Y.; Betul, C.; Melike, Y.; Benan, K.; Fatih, S. Highly efficient and monodisperse graphene oxide furnished Ru/Pd nanopaerticles for the dehalogenation of aryl halides via ammonia borane. ChemistrySelect, 2016, 1(5), 953-958.
[http://dx.doi.org/10.1002/slct.201600207]
[41]
Betul, S.; Sultan, K.; Enes, D.; Suleyman, A.; Fatih, S. Monodisperse palladium-nickel alloy nanoparticles assembled on graphene oxide with the high catalytic activity and reusability in the dehydrogenation of dimethyl amino borane. Int. J. Hyd. Eng., 2017, 42(36), 23276-23283.
[http://dx.doi.org/10.1016/j.ijhydene.2017.05.113]
[42]
Nandi, D.; Islam, R.U.; Devi, N.; Siwal, S.; Mallick, K. A palldium nanoparticle-catalyzed aryl-amine coupling reaction: high peformance of aryl and pyridyl chlorides as the coupling partner. New J. Chem., 2018, 42, 812-816.
[http://dx.doi.org/10.1039/C7NJ03447D]
[43]
Kalaiselvi, A.; Roopan, S.M.; Madhumitha, G.; Ramalingam, C.; Elango, G. Synthesis and characterization of palladium nanoparticles using Catharanthus roseus leaf extract and its application in the photo-catalytic degradation. Spectrochim. Acta A Mol. Biomol. Spectrosc., 2015, 135, 116-119.
[http://dx.doi.org/10.1016/j.saa.2014.07.010] [PMID: 25062057]
[44]
Aboelfetoh, E.F.; El-Shenody, R.A.; Ghobara, M.M. Eco-friendly synthesis of silver nanoparticles using green algae (Caulerpa serrulata): reaction optimization, catalytic and antibacterial activities. Environ. Monit. Assess., 2017, 189(7), 349.
[http://dx.doi.org/10.1007/s10661-017-6033-0] [PMID: 28646435]
[45]
Sharma, B.; Purkyastha, D.D.; Hazra, S.; Gogoi, L.; Bhattarcharjee, C.R.; Ghosh, N.N.; Rout, J. Biosynthesis of gold nanoparticles using fresh water alga prasiola crispa. Mater. Lett., 2013, 116, 94-97.
[http://dx.doi.org/10.1016/j.matlet.2013.10.107]
[46]
Shende, S.; Gade, A.; Rai, M. Large scale synthesis and antibacterial activity of fungal derived silver nanoparticles. Environ. Chem. Lett., 2016, 15, 427-434.
[http://dx.doi.org/10.1007/s10311-016-0599-6]
[47]
Elango, G.; Roopan, S.M.; Al-Dhabi, N.A.; Arasu, M.A.; Damodharan, K.I.; Elumalai, K. Cocos nucifera coir mediated green synthesis of PdNPs and its investigation against larvae and agricultural pest. Artif. Cells, 2016, 45(8), 1-7.
[48]
Sheny, D.S.; Philip, J.M. Green syntesis of palladium nanoparticles using the dried leaf of Anacardium occidentale. Spectrochim. Acta A Mol. Biolomol. Spectrosc., 2012, 91, 35-38.
[http://dx.doi.org/10.1016/j.saa.2012.01.063] [PMID: 22349890]
[49]
Farzaneh, A.; Mohammah, H.S.; Sara, S. Green synthesis of palladium nanoparticles using Chlorell vulgaris. Mater. Lett., 2017, 186, 113-115.
[http://dx.doi.org/10.1016/j.matlet.2016.09.101]
[50]
Mosayeb, S.; Roya, A. Buchwald-hartwig reaction of aryl halides using catalyst based on Pd nanoparticles decorated on chitosan functionalized graphene oxide. Appl. Organomet. Chem., 2018, 32e3906
[http://dx.doi.org/10.1002/aoc.3906]
[51]
Farhad, P.; Fatemeh, D.; Fatemeh, H.; Ali, K-N. Immobilized Pd nanoparticles on silica starch substrate (PNP-SSS): efficient heterogeneous catalyst in Buchwald-hartwig C-N cross coupling reaction. J. Organomet. Chem., 2017, 851, 210-217.
[http://dx.doi.org/10.1016/j.jorganchem.2017.09.037]

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