Oleg Ozerov
Associate Professor of Chemistry
Ph.D., University of Kentucky (2000)
781-736-2508
ozerov@brandeis.edu
group website
Research Interests
The prime theme of our research is the application of organometallic expertise to the solving of problems of making and breaking bonds in organic substrates. Our interests range from developing new catalysts for organic transformations to the environmentally important C-F activation studies. We strive to keep a balance between the pursuit of practical applications and more fundamental explorations. We are particularly interested in the mechanistic understanding of the elementary processes of bond making and breaking at transition metal centers. A requisite part of our work is the design and synthesis of novel polydentate ligands that impart desired reactivity preference on the metal center. We use a variety of physical methods such as NMR, IR, MS and X-Ray diffraction to interrogate compounds and reactions.
Metal-Carbon Multiple Bonds
Metal-carbon double and triple bonds are encountered in metal alkylidenes (carbenes) and alkylidynes (carbynes). Alkylidene and alkylidyne complexes are of particular importance as catalysts for metathesis of double and triple bonds in organic substrates. Olefin metathesis is an especially powerful synthetic tool. Our work entails the utilization of novel ligand scaffolds to create new metathesis catalysts of improved reactivity, stability and recyclability. As part of this research, we are interested in expanding the chemistry of alkylidene complexes and of metathesis to metals not traditionally considered for such purposes.
Robust Pd Catalysts for Coupling Reactions
Pd-based catalysts play an indispensable role in today’s synthetic organic chemistry. Key processes that are catalyzed by Pd compounds include the Heck, Stille, Suzuki, Sonogashira, and Buchwald-Hartwig coupling reactions. A large number of catalysts have been developed for these applications, yet there are still some directions in which major advancements can be made. We work to design new chelating ligands specifically to improve catalyst stability (towards air, high temperature, pendant functional groups), recyclability, and selectivity.
As a fundamentally captivating part of this work, we have come across several instances of cleavage of N-H and N-C bonds on Pd centers. Some of this chemistry can be extended to other metals and we have recently characterized a fascinating oxidative addition of an unstrained N-C(sp3) bond to Rh(I) and Ir(I).
Carbon-Fluorine Bond Activation
Fluorinated organic compounds have become ubiquitous in our lives. Fluorinated polymers, such as DuPont’s Teflon, are prized for their unique inertness and non-adhesiveness. Chlorofluorocarbons (CFCs or Freons) have been recognized as dangerous to the ozone layer. The less well-known fact is that CF4 and other perfluoroalkanes are extremely potent greenhouse gases, thousands of times more so than CO2. This seemingly obscure fact would have no bearing on our everyday life if only these volatile compounds were not by-products of the (obviously large-scale) industrial production of aluminum.
The ability to effectively functionalize C-F bonds would be quite desirable, but the challenge is in that C-F bonds are unreactive. The strongest single bond most elements make is the one to fluorine. Carbon-fluorine bond, in particular, is one of the strongest bonds known. We are developing main group and transition metal catalysts for functionalization of C-F bonds, most simply into C-H bonds. This may have potential in remediation of atmospheric pollutants (CFCs and perfluoroalkanes) and in production of partially fluorinated polymers.
Selected Publications
(19) Ozerov, O. V.; Guo, C.; Fan, L.; Foxman, B. M. “Oxidative Addition of N-C and N-H Bonds to Zero-Valent Nickel, Palladium, and Platinum”, Organometallics 2004, in press.
(18) Ozerov, O. V.; Watson, L. A.; Pink, M.; Caulton, K. G. "Terminal Acetylenes React to Increase Unsaturation in [(tBu2PCH2SiMe2)2N]Re(H)4", Organometallics 2004, in press.
(17) Weng, W.; Yang, L.; Foxman, B. M.; Ozerov, O. V."Chelate-Enforced Phosphine Coordination Enables a-Abstraction to Give Zirconium Alkylidenes", Organometallics 2004, in press.
(16) Fan, L.; Yang, L.; Guo, C.; Foxman, B. M.; Ozerov, O. V. "N-C cleavage in pincer PNP complexes of palladium", Organometallics 2004, in press.
(15) Ozerov, O. V.; Guo, C.; Papkov, V. A.; Foxman, B. M. "Facile Oxidative Addition of N-C and N-H Bonds to Monovalent Rhodium and Iridium", J. Am. Chem. Soc. 2004, 126, 4792.
(14) Fan, L.; Foxman, B. M.; Ozerov, O. V. "N-H Cleavage as a Route to Palladium Complexes of a New PNP Pincer Ligand", Organometallics 2004, 23, 326.
(13) Ozerov, O. V.; Watson, L. A.; Pink, M.; Caulton, K. G. "Transformation of Acyclic Alkenes to Hydrido Carbynes by (PNPR)Re Complexes", J. Am. Chem. Soc. 2004, 126, 6363.
(12) Ozerov, O. V.; Pink, M.; Watson, L. A.; Caulton, K. G. "Aromatic vs. Aliphatic C-H Cleavage of alkyl-Substituted Pyridines By (PNPiPr)Re Compounds", J. Am. Chem. Soc. 2004, 126, 2105.
(11) Ozerov, O. V.; Huffman, J. C.; Watson, L. A.; Caulton, K. G."Conversion of Ethylene to Hydride and Ethylidyne by an Amido Rhenium Polyhydride", Organometallics 2003, 22, 2539.
(10) Ozerov, O. V.; Watson, L. A.; Pink, M.; Caulton, K. G. "A p-basic Rhenium Center that Effects Cyclohexene Isomerization to a b-Agostic Carbene Ligand", J. Am. Chem. Soc. 2003, 125, 9604.
(9) Watson, L. A.; Ozerov, O.; Pink, M.; Caulton, K. G. "Four-coordinate, Planar Ru(II). A Triplet State as a Response to 14 Valence Electron Configuration", J. Am. Chem. Soc. 2003, 125, 8426.
(3) Ozerov, O. V.; Patrick, B. O.; Ladipo, F. T. "Highly Regioselective [2 + 2 + 2] Cycloaddition of Terminal Alkynes Catalyzed by h6-Arene Complexes of Titanium Supported by Dimethylsilyl-Bridged p-tert-Butyl Calix[4]arene Ligand", J. Am. Chem. Soc. 2000, 122, 6423.