A New Scaffold for Molecular Design: The Preparative Scale-Syntheses of Ru- Centered Arene Compounds

Page: [1148 - 1159] Pages: 12

  • * (Excluding Mailing and Handling)

Abstract

Carbon centered molecules have been very well recognized in the past for both academic and industrial purposes. Utilizing inert element instead of carbon atom could bring more molecular complexity as well as potential binding in medicinal chemistry. We report, herein, a number of strategies for the syntheses of Ru-centered molecules starting from commercially available [RuCl2(η6-p-cymene)] dimer substituted phenyl-heterocycles via Concerted Metalation Deprotonation (CMD) processes. Halogen atom ligand exchange and arene ligand exchange from the skeleton have been achieved. Under such procedures, a collectively good number of (26) Ru-arene complexes have been prepared efficiently. The Ru-complexes prepared have covered broad spectrum of functional groups on the 4 possible positions. Moreover, the Suzuki coupling reaction on the Ru-centered complex was realized with good yield (90%). The access of a library of these compounds would allow molecular chemists to consider the utilization of these molecules rather than purely organometallic reagents for inorganic chemistry or catalysis.

Keywords: Organometallic compound, CMD processes, molecular design, ruthenium arene complexes, C–H activation, arene exchange.

Graphical Abstract

[1]
Li, C.; Agarwal, J.; Schaefer, H.F. The remarkable [ReH9]2- dianion: molecular structure and vibrational frequencies. J. Phys. Chem. B, 2014, 118(24), 6482-6490.
[http://dx.doi.org/10.1021/jp412003s] [PMID: 24494734]
[2]
Therrien, B. Functionalised η6-arene Ruthenium complexes. Coord. Chem. Rev., 2009, 253, 493-519.
[http://dx.doi.org/10.1016/j.ccr.2008.04.014]
[3]
Levina, A.; Mitra, A.; Lay, P.A. Recent developments in ruthenium anticancer drugs. Metallomics, 2009, 1(6), 458-470.
[http://dx.doi.org/10.1039/b904071d] [PMID: 21305154]
[4]
Tan, X.; Wang, Q.; Liu, Y.; Wang, F.; Lv, H.; Zhang, X. A new designed hydrazine group-containing ruthenium complex used for catalytic hydrogenation of esters. Chem. Commun. (Camb.), 2015, 51(61), 12193-12196.
[http://dx.doi.org/10.1039/C5CC04242A] [PMID: 26132736]
[5]
Facchetti, S.; Jurcik, V.; Baldino, S.; Giboulot, S.; Nedden, H.G.; Gerosa, A.Z.; Blackaby, A.; Bryan, R.; Boogaard, A.; McLaren, D.B.; Moya, E.; Reynolds, S.; Sandham, K.S.; Martinuzzi, P.; Baratta, W. Preparation of Pincer 4-functionalized 2-aminomethylbenzo[h]quinoline ruthenium catalysts for ketone reduction. Organometallics, 2016, 35, 277-287.
[http://dx.doi.org/10.1021/acs.organomet.5b00978]
[6]
Sabater, S.; Bunz, H.M.; Albrecht, M. Carboxylate-functionalized mesoionic carbene precursors: decarboxylation, ruthenium bonding, and catalytic activity in hydrogen transfer reactions. Organometallics, 2016, 35, 2256-2266.
[http://dx.doi.org/10.1021/acs.organomet.6b00322]
[7]
Sommer, M.G.; Marinova, S.; Krafft, M.J.; Urankar, D.; Schweinfurth, D.; Bubrin, M.; Košmrlj, J.; Sarkar, B. Ruthenium azocarboxamide half-sandwich complexes: influence of the coordination mode on the electronic structure and activity in base-free transfer hydrogenation catalysis. Organometallics, 2016, 35, 2840-2849.
[http://dx.doi.org/10.1021/acs.organomet.6b00424]
[8]
Amenuvor, G.; Obuah, C.; Nordlander, E.; Darkwa, J. Novel pyrazolylphosphite- and pyrazolylphosphinite-ruthenium(ii) complexes as catalysts for hydrogenation of acetophenone. Dalton Trans., 2016, 45(34), 13514-13524.
[http://dx.doi.org/10.1039/C6DT02164F] [PMID: 27504937]
[9]
Nair, A.G.; McBurney, R.T.; Walker, D.B.; Page, M.J.; Gatus, M.R.D.; Bhadbhade, M.; Messerle, B.A. Ruthenium(ii) complexes of hemilabile pincer ligands: synthesis and catalysing the transfer hydrogenation of ketones. Dalton Trans., 2016, 45(36), 14335-14342.
[http://dx.doi.org/10.1039/C6DT02459A] [PMID: 27539740]
[10]
Liu, T.; Chai, H.; Wang, L.; Yu, Z. Exceptionally active assembled dinuclear ruthenium(II)-NNN complex catalysts for transfer hydrogenation of ketones. Organometallics, 2017, 36, 2914-2921.
[http://dx.doi.org/10.1021/acs.organomet.7b00356]
[11]
Kostera, S.; Wyrzykiewicz, B.; Pawluć, P.; Marciniec, B. Ruthenium-catalyzed deaminative redistribution of primary and secondary amines. Dalton Trans., 2017, 46, 11552-15555.
[12]
Telleria, A.; van Leeuwen, P.W.N.M.; Freixa, Z. Azobenzene-based ruthenium(ii) catalysts for light-controlled hydrogen generation. Dalton Trans, 2017, 46, 3569-3578.
[http://dx.doi.org/10.1021/acs.organomet.7b00721]
[13]
Jia, W.; Ling, S.; Zhang, H.; Sheng, E.; Lee, R. Half-sandwich ruthenium phenolate-oxazoline complexes: experimental and theoretical studies in catalytic transfer hydrogenation of nitroarene. Organometallics, 2018, 37, 40-47.
[http://dx.doi.org/10.1021/acs.organomet.7b00721]
[14]
Zhang, L.L.; Gao, Y.; Liu, Z.; Ding, X.; Yu, Z.; Sun, L.C. A trinuclear ruthenium complex as a highly efficient molecular catalyst for water oxidation. Dalton Trans., 2016, 45(9), 3814-3819.
[http://dx.doi.org/10.1039/C5DT04233J] [PMID: 26820507]
[15]
Wang, Q.; Chai, H.; Yu, Z. Acceptorless dehydrogenation of N-heterocycles and secondary alcohols by Ru(II)-NNC complexes bearing a pyrazoyl-indolylpyridine ligand. Organometallics, 2018, 37, 584-591.
[http://dx.doi.org/10.1021/acs.organomet.7b00902]
[16]
Arockiam, P.B.; Bruneau, C.; Dixneuf, P.H. Ruthenium(II)-catalyzed C-H bond activation and functionalization. Chem. Rev., 2012, 112(11), 5879-5918.
[http://dx.doi.org/10.1021/cr300153j] [PMID: 22934619]
[17]
Ritleng, V.; Sirlin, C.; Pfeffer, M. Ru-, Rh-, and Pd-catalyzed C-C bond formation involving C-H activation and addition on unsaturated substrates: reactions and mechanistic aspects. Chem. Rev., 2002, 102(5), 1731-1770.
[http://dx.doi.org/10.1021/cr0104330] [PMID: 11996548]
[18]
Li, J.; De Sarkar, S.; Ackermann, L. Meta- and para-selective C−H functionalization by C−H activation. in: C-H Bond Activation and Catalytic Functionalization . i. pierre h.; doucet, d.n. ed;Springer International Publishing: Cham, 2016, Vol. 55, pp. 217-257.
[19]
Ferrer Flegeau, E.; Bruneau, C.; Dixneuf, P.H.; Jutand, A. Autocatalysis for C-H bond activation by ruthenium(II) complexes in catalytic arylation of functional arenes. J. Am. Chem. Soc., 2011, 133(26), 10161-10170.
[http://dx.doi.org/10.1021/ja201462n] [PMID: 21604765]
[20]
Zhang, L.; Li, L.; Wang, Y.; Yang, Y.; Liu, X.; Liang, Y. Ruthenium-catalyzed direct C−H amidation of arenes: a mechanistic study. Organometallics, 2014, 33, 1905-1908.
[http://dx.doi.org/10.1021/om500080z]
[21]
Wilkinson, L.A.; Pike, J.A.; Walton, J.W. C−H Activation of π-arene ruthenium complexes. Organometallics, 2017, 36, 4376-4381.
[http://dx.doi.org/10.1021/acs.organomet.7b00563]
[22]
Leitch, J.A.; Heron, C.J.; McKnight, J.; Köhn, G.K.; Bhonoah, Y.; Frost, C.G. Ruthenium catalyzed remote C4-selective C-H functionalisation of carbazoles via σ-activation. Chem. Commun. (Camb.), 2017, 53(97), 13039-13042.
[http://dx.doi.org/10.1039/C7CC07606A] [PMID: 29164185]
[23]
Li, Z.Y.; Li, L.; Li, Q.L.; Jing, K.; Xu, H.; Wang, G.W. Ruthenium-Catalyzed meta-Selective C-H Mono- and Difluoromethylation of Arenes through ortho-Metalation Strategy. Chemistry, 2017, 23(14), 3285-3290.
[http://dx.doi.org/10.1002/chem.201700354] [PMID: 28120380]
[24]
Zhou, T.; Li, L.; Li, B.; Song, H.; Wang, B. Syntheses, structures, and reactions of cyclometalated rhodium, iridium, and ruthenium complexes of N-methoxy-4-nitrobenzamide. Organometallics, 2018, 37, 476-481.
[http://dx.doi.org/10.1021/acs.organomet.7b00879]
[25]
Li, B.; Roisnel, T.; Darcel, C.; Dixneuf, P.H. Cyclometallation of arylimines and nitrogen-containing heterocycles via room-temperature C-H bond activation with arene ruthenium(II) acetate complexes. Dalton Trans., 2012, 41(36), 10934-10937.
[http://dx.doi.org/10.1039/c2dt31401k] [PMID: 22890507]
[26]
Kajikawa, A.; Togashi, T.; Orikasa, Y.; Cui, B.B.; Zhong, Y.W.; Sakamoto, M.; Kurihara, M.; Kanaizuka, K. Construction of hybrid films of silver nanoparticles and polypyridine ruthenium complexes on substrates. Dalton Trans., 2015, 44(34), 15244-15249.
[http://dx.doi.org/10.1039/C5DT00563A] [PMID: 25986241]
[27]
Nakamura, G.; Kondo, M.; Crisalli, M.; Lee, S.K.; Shibata, A.; Ford, P.C.; Masaoka, S. Syntheses and properties of phosphine-substituted ruthenium(II) polypyridine complexes with nitrogen oxides. Dalton Trans., 2015, 44(39), 17189-17200.
[http://dx.doi.org/10.1039/C5DT02994E] [PMID: 26373342]
[28]
Hollering, M.; Albrecht, M.; Kühn, F.E. Bonding and catalytic application of ruthenium N-heterocyclic carbene complexes featuring triazole, triazolylidene, and imidazolylidene ligands. Organometallics, 2016, 35, 2980-2986.
[http://dx.doi.org/10.1021/acs.organomet.6b00504]
[29]
Schleicher, D.; Tronnier, A.; Leopold, H.; Borrmann, H.; Strassner, T. Unusual dimer formation of cyclometalated ruthenium NHC p-cymene complexes. Dalton Trans., 2016, 45(8), 3260-3263.
[http://dx.doi.org/10.1039/C6DT00100A] [PMID: 26839062]
[30]
Kreitner, C.; Heinze, K. Excited state decay of cyclometalated polypyridine ruthenium complexes: insight from theory and experiment. Dalton Trans., 2016, 45(35), 13631-13647.
[http://dx.doi.org/10.1039/C6DT01989G] [PMID: 27334798]
[31]
Lenis-Rojas, O.A.; Fernandes, A.R.; Roma-Rodrigues, C.; Baptista, P.V.; Marques, F.; Fernández, D.P.; Varela, J.G.; Sánchez, L.; García, D.V.; Torres, M.L.; Fernández, A.; Fernández, J.J. Heteroleptic mononuclear compounds of ruthenium(ii): synthesis, structural analyses, in vitro antitumor activity and in vivo toxicity on zebrafish embryos. Dalton Trans., 2016, 45(47), 19127-19140.
[http://dx.doi.org/10.1039/c6dt03591d] [PMID: 27868117]
[32]
Ghebreyessus, K.; Cooper, S.M. Photoswitchable arylazopyrazole-based ruthenium(II) arene complexes. Organometallics, 2017, 36, 3360-3370.
[http://dx.doi.org/10.1021/acs.organomet.7b00493]
[33]
Clavel, C.M.; Păunescu, E.; Sliwinska, P.N; Griffioen, A.W.; Scopelliti, R.; Dyson, P.J. Modulating the anticancer activity of ruthenium(II)-arene complexes. J. Med. Chem., 2015, 58(8), 3356-3365.
[http://dx.doi.org/10.1021/jm501655t] [PMID: 25812075]
[34]
nikolić. S.; Opsenica, DM.; Filipović, V.; Dojčinović, B.; Aranđelović, S.; Radulović, S.; Šipka, S.G. Strong in vitro cytotoxic potential of new ruthenium-cymene complexes. Organometallics, 2015, 34, 3464-3473.
[http://dx.doi.org/10.1021/acs.organomet.5b00041]
[35]
Pettinari, R.; Marchetti, F.; Petrini, A.; Pettinari, C.; Lupidi, G.; Smoleński, P.; Scopelliti, R.; Riedel, T.; Dyson, P.J. From sunscreen to anticancer agent: ruthenium(II) arene avobenzone complexes display potent anticancer activity. Organometallics, 2016, 35, 3734-3742.
[http://dx.doi.org/10.1021/acs.organomet.6b00694]
[36]
Elumalai, P.; Jeong, Y.J.; Park, D.W.; Kim, D.H.; Kim, H.; Kang, S.C.; Chi, K.W. Antitumor and biological investigation of doubly cyclometalated ruthenium(II) organometallics derived from benzimidazolyl derivatives. Dalton Trans., 2016, 45(15), 6667-6673.
[http://dx.doi.org/10.1039/C5DT04400F] [PMID: 26974823]
[37]
Mitrović, A.; Kljun, J.; Sosič, I.; Gobec, S.; Turel, I.; Kos, J. Clioquinol-ruthenium complex impairs tumour cell invasion by inhibiting cathepsin B activity. Dalton Trans., 2016, 45(42), 16913-16921.
[http://dx.doi.org/10.1039/C6DT02369J] [PMID: 27711842]
[38]
Su, W.; Tang, Z.; Li, P.; Wang, G.; Xiao, Q.; Li, Y.; Huang, S.; Gu, Y.; Lai, Z.; Zhang, Y. New dinuclear ruthenium arene complexes containing thiosemicarbazone ligands: synthesis, structure and cytotoxic studies. Dalton Trans., 2016, 45(48), 19329-19340.
[http://dx.doi.org/10.1039/C6DT03306G] [PMID: 27872925]
[39]
Biancalana, L.; Batchelor, L.K.; De Palo, A.; Zacchini, S.; Pampaloni, G.; Dyson, P.J.; Marchetti, F. A general strategy to add diversity to ruthenium arene complexes with bioactive organic compounds via a coordinated (4-hydroxyphenyl)diphenylphosphine ligand. Dalton Trans., 2017, 46(36), 12001-12004.
[http://dx.doi.org/10.1039/C7DT02062G] [PMID: 28627572]
[40]
Grozav, A.; Balacescu, O.; Balacescu, L.; Cheminel, T.; Berindan-Neagoe, I.; Therrien, B. Synthesis, anticancer activity, and genome profiling of thiazolo arene ruthenium complexes. J. Med. Chem., 2015, 58(21), 8475-8490.
[http://dx.doi.org/10.1021/acs.jmedchem.5b00855] [PMID: 26488797]
[41]
Wambang, N.; Faux, N.S.; Martoriati, A.; Henry, N.; Baldeyrou, B.; Mahieu, C.B.; Bousquet, T.; Pellegrini, S.; Meignan, S.; Cailliau, K.; Goossens, J.F.; Bodart, J.F.; Ndifon, P.T.; Pélinski, L. Synthesis, structure, and antiproliferative activity of ruthenium(II) arene complexes of indenoisoquinoline derivatives. Organometallics, 2016, 35, 2868-2872.
[http://dx.doi.org/10.1021/acs.organomet.6b00440]
[42]
Maganña, Y.M.; Ramos, J.C.G.; Gutiérres, C.T.; Gasser, C.V.; sánchez, J.M.E.; Alamo, M.F.; Frade, L.O.; Murillo, R.G.; Nequiz, M.; Zayas, M.G.; Laclette, J.P.; Carrero, J.C.; Azuara, L.R. Water-soluble ruthenium (II) chiral heteroleptic complexes with amoebicidal in vitro and in vivo activity. J. Med. Chem., 2017, 60, 899-912.
[43]
Ekengard, E.; Glans, L.; Cassells, I.; Fogeron, T.; Govender, P.; Stringer, T.; Chellan, P.; Lisensky, G.C.; Hersh, W.H.; Doverbratt, I.; Lidin, S.; de Kock, C.; Smith, P.J.; Smith, G.S.; Nordlander, E. Antimalarial activity of ruthenium(II) and osmium(II) arene complexes with mono- and bidentate chloroquine analogue ligands. Dalton Trans., 2015, 44(44), 19314-19329.
[http://dx.doi.org/10.1039/C5DT02410B] [PMID: 26491831]
[44]
Cloonan, S.M.; Elmes, R.B.P.; Erby, M.; Bright, S.A.; Poynton, F.E.; Nolan, D.E.; Quinn, S.J.; Gunnlaugsson, T.; Williams, D.C. Detailed biological profiling of a photoactivated and apoptosis inducing pdppz ruthenium(II) polypyridyl complex in cancer cells. J. Med. Chem., 2015, 58(11), 4494-4505.
[http://dx.doi.org/10.1021/acs.jmedchem.5b00451] [PMID: 25961430]
[45]
Ryan, G.J.; Poynton, F.E.; Elmes, R.B.P.; Erby, M.; Williams, D.C.; Quinn, S.J.; Gunnlaugsson, T. Unexpected DNA binding properties with correlated downstream biological applications in mono vs. bis-1,8-naphthalimide Ru(II)-polypyridyl conjugates. Dalton Trans., 2015, 44(37), 16332-16344.
[http://dx.doi.org/10.1039/C5DT00360A] [PMID: 26305507]
[46]
Chang, Y.H.; Leu, W.J.; Datta, A.; Hsiao, H-C.; Lin, C.H.; Guh, J.H.; Huang, J.H. Catalytic transfer hydrogenation and anticancer activity of arene-ruthenium compounds incorporating bi-dentate precursors. Dalton Trans., 2015, 44(36), 16107-16118.
[http://dx.doi.org/10.1039/C5DT01310K] [PMID: 26287471]
[47]
Lazić, D.; Arsenijević, A.; Puchta, R.; Bugarčić, Ž.D.; Rilak, A. DNA binding properties, histidine interaction and cytotoxicity studies of water soluble ruthenium(ii) terpyridine complexes. Dalton Trans., 2016, 45(11), 4633-4646.
[http://dx.doi.org/10.1039/C5DT04132E] [PMID: 26855406]
[48]
Díaz, M.M.; Elie, B.T.; Sal, P.G.; Serrano, J.P.; Gómez, R.; Contel, M.; Mata, F.j. Synthesis and anticancer activity of carbosilane metallodendrimers based on arene ruthenium(ii) complexes. Dalton Trans., 2016, 45(16), 7049-7066.
[http://dx.doi.org/10.1039/C6DT00465B] [PMID: 26990859]
[49]
Zhang, J.J.; Muenzner, J.K.; Abu El Maaty, M.A.; Karge, B.; Schobert, R.; Wölfl, S.; Ott, I. A multi-target caffeine derived rhodium(i) N-heterocyclic carbene complex: evaluation of the mechanism of action. Dalton Trans., 2016, 45(33), 13161-13168.
[http://dx.doi.org/10.1039/C6DT02025A] [PMID: 27334935]
[50]
Li, G.; Sun, L.; Ji, L.; Chao, H. Ruthenium(ii) complexes with dppz: from molecular photoswitch to biological applications. Dalton Trans., 2016, 45(34), 13261-13276.
[http://dx.doi.org/10.1039/C6DT01624C] [PMID: 27426487]
[51]
Fang, L.; Liu, S.; Han, L.; Li, H.; Zhao, F. Ruthenium-catalyzed synthesis of cis-2,3-dihydrobenzofuran-3-ols by aqueous transfer hydrogenation via dynamic kinetic resolution. Organometallics, 2017, 36, 1217-1219.
[http://dx.doi.org/10.1021/acs.organomet.7b00022]
[52]
Meggers, E. Exploiting octahedral stereocenters: from enzyme inhibition to asymmetric photoredox catalysis. Angew. Chem. Int. Ed. Engl., 2017, 56(21), 5668-5675.
[http://dx.doi.org/10.1002/anie.201612516] [PMID: 28328151]
[53]
Blanck, S.; Maksimoska, J.; Baumeister, J.; Harms, K.; Marmorstein, R.; Meggers, E. The art of filling protein pockets efficiently with octahedral metal complexes. Angew. Chem. Int. Ed. Engl., 2012, 51(21), 5244-5246.
[http://dx.doi.org/10.1002/anie.201108865] [PMID: 22383326]
[54]
Huang, H.; Zhang, P.; Yu, B.; Chen, Y.; Wang, J.; Ji, L.; Chao, H. Targeting nucleus DNA with a cyclometalated dipyridophenazineruthenium(II) complex. J. Med. Chem., 2014, 57(21), 8971-8983.
[http://dx.doi.org/10.1021/jm501095r] [PMID: 25313823]
[55]
Yu, Q.; Hu, L.; Wang, Y.; Zheng, S.; Huang, J. Directed meta-selective bromination of arenes with ruthenium catalysts. Angew. Chem. Int. Ed. Engl., 2015, 54(50), 15284-15288.
[http://dx.doi.org/10.1002/anie.201507100] [PMID: 26517831]
[56]
Winstein, S.; Traylor, T.G. Mechanisms of reaction of organomercurials. ii. electrophilic substitution on saturated carbon. Acetolysis of dialkylmercury compounds. J. Am. Chem. Soc., 1955, 77, 3747-3752.
[http://dx.doi.org/10.1021/ja01619a021]
[57]
Muetterties, E.L.; Bleeke, J.R.; Wucherer, E.J.; Albright, T. Structural, stereochemical, and electronic features of arene-metal complexes. Chem. Rev., 1982, 82, 499-525.
[http://dx.doi.org/10.1021/cr00051a002]
[58]
Pampaloni, G. Aromatic hydrocarbons as ligands. Recent advances in the synthesis, the reactivity and the applications of bis(η6-arene) complexes. Coord. Chem. Rev., 2010, 254, 402-419.
[http://dx.doi.org/10.1016/j.ccr.2009.05.014]
[59]
Perekalin, D.S.; Karslyan, E.E.; Petrovskii, P.V.; Borissova, A.O.; Lyssenko, K.A.; Kudinov, A.R. Arene exchange in the ruthenium-naphthalene complex [CpRu(C10H8)]+. Eur. J. Inorg. Chem., 2012, 2012, 1485-1492.
[http://dx.doi.org/10.1002/ejic.201100928]
[60]
Hayashida, T.; Nagashima, H. Access to novel ruthenium-amidinate complexes, (η6-arene)Ru(η6-amidinate)X and [Ru(η2-amidinate)(MeCN)4]+PF6- by photochemical displacement of the benzene ligand in (η6-C6H6)Ru(η2-amidinate)X. Organometallics, 2002, 21, 3884-3888.
[http://dx.doi.org/10.1021/om020227y]
[61]
Shibasaki, T.; Komine, N.; Hirano, M.; Komiya, S. Synthesis of di-, tri-, tetra- and pentacyclic arene complexes of ruthenium(II):[Ru(η6-polycyclic arene)-(1-5-η5-cyclooctadienyl)]PF6 and their reactions with NaBH4. J. Organomet. Chem., 2007, 692, 2385-2394.
[http://dx.doi.org/10.1016/j.jorganchem.2007.02.023]
[62]
Choi, M.G.; Ho, T.C.; Angelici, R.J. Arene binding affinities in [CpRu(η6-arene)]+ complexes: models for the adsorption of arenes on hydrodesulfurization catalysts. Organometallics, 2008, 27, 1098-1105.
[http://dx.doi.org/10.1021/om700773j]
[63]
Bennett, M.A.; Smith, A.K. Arene ruthenium(II) complexes formed by dehydrogenation of cyclohexadienes with ruthenium(III) trichloride. J. Chem. Soc., Dalton Trans., 1974, 2, 233-241.
[http://dx.doi.org/10.1039/dt9740000233]
[64]
Li, B.; Darcel, C.; Roisnel, T.; Dixneuf, P.H. Cycloruthenation of aryl imines and N-heteroaryl benzenes via C–H bond activation with Ru(II) and acetate partners. J. Organomet. Chem., 2015, 793, 200-209.
[http://dx.doi.org/10.1016/j.jorganchem.2015.02.050]
[65]
Díaz, O.S.; Camacho, R.C.; Ryabov, A.D.; Lagadec, R.L. Denial of tris(C,Ncyclometalated) ruthenacycle: nine-membered η6-N,N-trans or η2-N,N-cis RuII chelates of 2,2′-bis(2-pyridinyl)-1,1′-biphenyl. Eur. J. Inorg. Chem., 2008, 31, 4866-4869.
[http://dx.doi.org/10.1002/ejic.200800584]