Page 14 - MetalLigand Cooperation by AromatizationDearomatization: A New Paradigm in Bond Activation and Green Catalysis

MetalLigand Cooperation Gunanathan and Milstein

metal center, make the PNN and PNP ligands highly effective a Group Leader in the homogeneous catalysis area. In 1987 he
motifs for metalligand cooperation. These heteroaromatic accepted a professorial appointment at the Weizmann Institute of
Science in Israel, where he became Head of the Department of
pincer ligands act in concert with metal center in the activation
Organic Chemistry in 1996 until 2005. In 2000 he became Head of
of strong bonds, such as CH, HH, NH, and OHbonds,
the Kimmel Center for Molecular Design. He is the Israel Matz
providing a new approach to bond activation and a basis for
Professor of Organic Chemistry since 1996. His research interests
catalytic design. Guided by these modes of metalligand focus on the development of fundamental organometallic chemistry
cooperation, novel, highly efficient atom economical, and en- and its application to the design of new sustainable processes
vironmentally benign methods were developed for a range of catalyzed by transition metal complexes. Awards received include
products directly from alcohols with the liberation of H 2 ,a the KolthoffPrize,theIsraelChemicalSocietyAward,theACSAwardin
Organometallic Chemistry, the RSC Sir Geoffrey Wilkinson Prize, and
significant departure from the conventional synthetic proce-
the Meitner Humboldt ResearchAward.He was electedtothe German
dures. While we have disclosed cooperative catalysis by ruthe-
National Academy of Sciences-Leopoldina in 2006.
nium and iron pincer complexes, catalytic studies involving
pincer complexes of other transition metal complexes are FOOTNOTES
currently in progress in our laboratories. In recent years, the *To whom correspondence should be addressed. E-mail: david.milstein@weizmann.ac.il.
research areas of cooperativity incatalysis by metal complexes,
and the broad field of pincer complexes, have gained much REFERENCES
1 Beller, M., Bolm, C., Eds. Transition Metals for Organic Synthesis; Wiley-VCH: Weinheim,
interest. As shown in this Account, combining these two areas
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within the theme of pincer-complex cooperativity can lead to 2 (a) Noyori,R.;Koizumi,M.;Ishii, D.;Ohkuma, T. Asymmetrichydrogenation via architectural
and functional molecularengineering.Pure Appl.Chem. 2001,73,227–232. (b) Clapham,
new bond activation modes and to unprecedented, green S. E.; Hadzovic, A.; Morris, R. H. Mechanisms of the H 2 -hydrogenation and transfer
catalytic reactions. hydrogenation of polar bonds catalyzed by ruthenium hydride complexes. Coord. Chem.
Rev. 2004, 248, 2201–2237. (c) Casey, C. P.; Bikzhanova, G. A.; Cui, Q.; Guzei, I. L.
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We thank all our co-workers, whose names appear in the cited evidence for hydride and proton transfer outside the coordination sphere of the metal. J.
Am. Chem. Soc. 2005, 127, 14062–14071. (d) Ikariya, T.; Blacker, A. J. Asymmetric
references, for their valuable contributions. This research was sup- transfer hydrogenation of ketones with bifunctional transition metal-based molecular
catalysts. Acc. Chem. Res. 2007, 40,1300–1308. (e) Grutzmacher, H. Cooperating
ported by the European Research Council under the FP7 framework
ligands in catalysis. Angew. Chem., Int. Ed. 2008, 47, 1814–1818.
(ERC No 246837), by the Israel Science Foundation, by the MINERVA 3 Morales-Morales, D., Jensen, C. M., Eds. The Chemistry of Pincer Compounds; Elsevier:
Amsterdam, 2007.
Foundation, by the DIP Program for German-Israeli Cooperation, by
4 For comprehensive reviews on pincer complexes, see: (a) Albrecht, M.; Van Koten, G.
the Kimmel Center for Molecular Design, and by the Peter J. Cohn Platinum group organometallics based on “pincer” complexes: sensors, switches, and
catalysts. Angew. Chem., Int. Ed. 2001, 40,3750–3781. (b) Van der Boom, M. E.;
Fund. D.M. is the holder of the Israel Matz Professorial Chair.
Milstein, D. Cyclometalated phosphine-based pincer complexes: mechanistic insight in
catalysis, coordination, and bond activation. Chem. Rev. 2003, 103, 1759–1792.
5 vanderVlugt, J. L.; Reek, J. N. H. Neutral tridentate PNPligandsandtheirhybridanalogues:
BIOGRAPHICAL INFORMATION versatile non-innocent scaffolds for homogeneous catalysis. Angew. Chem., Int. Ed. 2009,
48, 8832–8846.
Chidambaram Gunanathan received his B.Sc (chemistry) and
6 (a) Milstein, D. Discovery of environmentally benign catalytic reactions of alcohols catalyzed
M.Sc (organic chemistry) from University of Madras, India. He was by pyridine-based pincer Ru complexes, based on metalligand cooperation. Top. Catal.
awarded a Ph.D in chemistry for his research work at Central Salt 2010, 53, 915–923. (b) Gunanathan, C.; Milstein, D. Bond Activation by MetalLigand
Cooperation: Design of “Green” Catalytic Reactions Based on Aromatiza-
and Marine Chemicals Research Institute, Bhavnagar, India with tionDearomatization of Pincer Complexes. Top. Organomet. Chem. 2011, DOI:
Prof. S. Muthusamy. In 2005, he joined in the groups of Prof. David 10.1007/3418_2011_6.
Milstein and Prof. Hadassa Degani at Weizmann Institute of 7 Zhang, J.; Leitus, G.; Ben-David, Y.; Milstein, D. Facile conversion of alcohols into esters
and dihydrogen catalyzed by new ruthenium complexes. J. Am. Chem. Soc. 2005, 127,
Science, Israel for his postdoctoral stint, where he was also a Dean 10840–10840.
of Faculty Postdoctoral Fellow. He also worked with the group of 8 Ben-Ari,E.;Leitus, G.;Shimon,L.J. W.;Milstein, D. Metal-ligandcooperationinC-H andH 2
Prof. Walter Leitner at RWTH Aachen University, Germany as an activation by an electron-rich PNP Ir(I) system: facile ligand dearomatization-aromatization
as key steps. J. Am. Chem. Soc. 2006, 128, 15390–15391.
Alexander von Humboldt Research Fellow. In May 2011, he joined 9 Zhang, J.; Leitus, G.; Ben-David, Y.; Milstein, D. Efficient homogeneous catalytic
as Assistant Professor at the National Institute of Science Education hydrogenation of esters to alcohols. Angew. Chem., Int. Ed. 2006, 45, 1113–1115.
and Research, Bhubaneswar, India. He is also a recipient of 10 Vuzman, D.; Poverenov, E.; Shimon, L. J. W.; Diskin-Posner, Y.; Milstein, D. Cationic,
neutral, and anionic platinum(II) complexes based on an electron-rich PNN ligand. New
Ramanujan Fellowship from DST, New Delhi. His research interests modes of reactivity based on pincer hemilability and dearomatization. Organometallics
are the design and catalytic application of pincer complexes and 2008, 27, 2627–2634.
discovery of new reactions for atom economy. 11 Ben-Ari, E.; Gandelman, M.; Rozenberg, H.; Shimon, L. J. W.; Milstein., D. Selective Ortho
C-HActivation of HaloarenesbyanIr(I) System.J.Am.Chem.Soc.2003,125, 4714–4715.
David Milstein received his Ph.D degree at the Hebrew University 12 Ben-Ari,E.;Cohen, R.; Gandelman, M.; Shimon, L.J. W.; Martin,J. M. L.;Milstein, D.ortho
of Jerusalem in 1976. He carried out postdoctoral studies at Colorado CH activation of haloarenes and anisole by an electron-rich iridium(I) complex:
State University, where together with his advisor, John Stille, he mechanism and origin of regio- and chemoselectivity. An experimental and theoretical
study. Organometallics 2006, 25, 3190–3210.
discovered the Stille Reaction. In 1979 he joined the CR&D Depart- 13 Schwartsburd, L.; Iron, M. A.; Konstantinovski, L.; Diskin-Posner, Y.; Leitus, G.; Shimon,
ment of the DuPont Company in the United States, where he became L. J. W.; Milstein, D. Synthesis and reactivity of an iridium(I) acetonyl PNP complex.

Vol. 44, No. 8 ’ 2011 ’ 588–602 ’ ACCOUNTS OF CHEMICAL RESEARCH ’ 601