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Linda S. Jongbloed , S. Y. de Boer, J. N. H. Reek, J. I. van der Vlugt . Cooperative ( Dinucleating ) systems for E-H Bond activation. Homogeneous and Supramolecular Catalysis van ‘t Hoff Institute for Molecular Sciences University of Amsterdam. EWPC 19 March 2013.
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Linda S. Jongbloed, S. Y. de Boer, J. N. H. Reek, J. I. van der Vlugt Cooperative (Dinucleating) systems for E-H Bond activation HomogeneousandSupramolecularCatalysis van ‘t Hoff Institute for Molecular Sciences University of Amsterdam EWPC 19 March 2013
E-H activationandcatalysis Hydroamination: Activation of N-H, O-H, S-H andsubsequentcatalyticreactionssuch as hydroadditionreactions
Cooperative ligand systems • Spectator ligands • Oxidation state of metal raiseswith 2 • Non-innocent ligands • No formal change in oxidation state of metal • Ligand participates in catalyticcycle J. I. van der Vlugt, Eur. J. Inorg. Chem.2012, 3, 363-375
Cooperative ligands: examples Noyori Hydrogenation of ketones Ikariya Intramolecularhydroamination Grützmacher Hydrogenation T. Ikariya, K. Murata, R. Noyori, Org. Biomol. Chem. 2006, 4, 393. Y. Kashiwame, S. Kuwata, T. Ikariya, Chem. Eur. J.2010, 16, 766. P. Maire, T. Büttner, F. Breher, P. Le Floch, H. Grützmacher, Angew. Chem. Int. Ed. 2005, 117, 6477
Cooperative ligands: examples Milstein Hydrogenation, hydrogenolysis, dehydrogenativecoupling van der Vlugt S-H activation, C-C coupling C. Gununanathan, D. Milstein, Acc. Chem. Res201, 44, 588-602. J. I. van der Vlugt, E. A. Pidko, R. C. Bauer, Y. Gloaguen, M. K. Rong, M. Lutz, Chem. Eur. J. 2011, 17, 3850. J. I. van der Vlugt, E. A. Pidko, D. Vogt, M. Lutz, A. L. Spek, Inorg. Chem. 2009, 48, 7513-7515. J. I. van der Vlugt, J. N. H. Reek, Angew. Chem. Int. Ed. 2009, 48, 8832-8846.
Dinuclearactivation In enzymes, active sites often have dinuclearcores Combine bimetalliccooperativitywith ligand non-innocence F. Gloaguen and T. B. Rauchfuss, Chem. Soc. Rev., 2009, 38, 100–108.
Goals • Development of new cooperative ligands with proton transfer reactivity • Dinucleating ligands • Activation of E-H bonds andsubsequenthydroadditionreactions
Design new ligands • PN: Bidentatevstridentate- additional vacant site • PN(C): uniquetype of cooperativity PNP: occupationof threecoordination sites Activation of substratespossible Subsequenthydroadditionsnotyetaccomplished
PN ligand- Pd X • Isolation leads to decomposition JP-P = 439 Hz S. Y. de Boer, Y. Gloaguen, J. N. H. Reek, M. Lutz, J. I. van der Vlugt, Dalton Trans. 2012, 41, 11276-11283
CNP ligand Reversibleorthometalation? Dearomatizationreactivity Unexpectedorthometalation is observed Phosphorus is strong trans ligand – reversibleorthometalation? Versatile ligand withtwocooperative sites
CNP ligand - Pd: N-H activation • Reversibleorthometalation Dearomatization
CNP ligand - Pd: N-H activation 31P NMR spectra A B C D
CNP ligand - Rh: reactivity ? = agostic C-H, π-interaction of phenyl ring, CH2Cl2 Rh-C canbecleavedby strong electrophiles Alsobyweakacids (NH4PF6, HCOOH) So far no N-H activation
CNP ligand - Rh 31P NMR spectra A JRh-P 101 Hz JRh-P 163 Hz B JRh-P 170 Hz C JRh-P 203 Hz D
Dinucleating ligand Bimetallic rhodium complex shows similarbehaviour as mono-nuclear complex Palladium complex does not show desiredreactivity Investigations in bimetallicactivations are ongoing
Conclusions • PN ligand • CNP ligand • Dearomatization • Reversible C-H activation
Acknowledgements Sandra Y. de Boer MSc. Dr. Ir. Jarl Ivar van der Vlugt Prof. dr. Bas de Bruin Prof. dr. Joost N. H. Reek
CNP ligand - Rh: S-H activation Unexpected de-coordination of pyridine moiety Alsopossiblewitharomaticandbenzylicmercaptans
Hydroamination • Challenges in hydroamination: • Intermolecularhydroamination • Linearanti-Markovnikov product • Hydroaminationwithprimaryaminesand ammonia (NH3)
Aim • Gainfundamentalunderstandingandinsight in activationprocessesandsubsequentreactivity • Improvesyntheticmethodologiesfororganic / pharmaceuticalprocesses • Atom efficiency • Neutral conditions
Research start Ligand design: pyridine dearomatization