Aaron Odom
Professor Office: 433 Chemistry
Phone: 517-355-9715 171 /
Websites: Research Group - Area
Awards & Honors
Genealogy/Graduates
Organometallic/Inorganic Synthesis and Transition Metal Catalysis in Organic Synthesis
(Research Description PDF - 914 kb)Metal-ligand multiple bonds between the transition metals and p-block elements have a large and expanding role in many important catalytic processes ranging from common carbon-carbon bond forming reactions like olefin metathesis to intermediates in dinitrogen reduction like hydrazido(2-) complexes. Our research group is exploring the properties and reactivity of these metal-ligand multiple bond complexes with a focus on their utilization in novel syntheses of heterocycles, polymers, and other products.
In one application, we are exploring the use of a titanium-catalyzed multicomponent coupling reaction in heterocyclic synthesis. For these titanium reactions, we have developed a large selection of deprotonated, pyrrole-based ancillary ligands. These ligands seem to provide advantageous reactivity at the metal center over other systems and are often prepared in a single step. For example, the most common ligand used in this chemistry is the simple dipyrrolylmethane derived from reaction of pyrrole and acetone (Hdpm), which can be placed on the metal center by transamination with Ti(NMe2)4 in near quantitative yield.
The complex above catalyzes the multicomponent coupling between an alkyne, isonitrile, and primary amine in a formal iminoamination of the alkyne. The product is a tautomer of a 1,3-diimine. The proposed mechanism for the reaction along with the overall reaction is shown in the Scheme below.
This multicomponent coupling reaction allows access to these unsymmetrical 1,3-dicarbonyl derivatives, which have a host of applications. We have developed several one-pot procedures to different heterocycles based on the above reaction already and many more are possible. For example, we have used the above reaction in one-pot procedures to generate quinolines, pyrazoles, and pyrimidines. The multicomponent routes to heterocycles have been applied to the synthesis of biologically active natural products.
In a separate project, our group is exploring the synthesis and reactivity of an intriguing class of metallacycles having two different metal-ligand multiple bonds in the same ring. These compounds have interesting properties as polymerization catalysts and have subtle electronic differences with their nonmetallacyclic analogs, i.e. Schrock's catalyst.
Through projects aimed at deepening our knowledge of the electronic structure and synthesis of metal-ligand multiple bonds, we are attempting to enrich the applications of molecules in this class.
Selected Publications
New C?N and C?C Bond Forming Reactions Catalyzed by Titanium Complexes, A. L. Odom, Dalton Transactions 2005, 2, 225.Titanium Hydrazido Complexes: Synthesis, Structure, Reactivity, and Relevance to Alkyne Hydroamination, Y. Li, A. L. Odom, J. Am. Chem. Soc. 2004, 126, 1794.
A Titanium-catalyzed 3-Component Coupling to Generate a, ß-Unsaturated ß-Iminoamines, C. Cao, Y. Shi, A. L. Odom, J. Am. Chem. Soc. 2003, 125(10), 2880.
Titanium Dipyrrolylmethane Derivatives: Rapid Intermolecular Alkyne Hydroamination, Y. Shi, C. Hall, J. T. Ciszewski, C. Cao, A. L. Odom, Chem. Commun. 2003, 5, 586.
Synthesis and Structure of an Imido-Tethered Schrock Carbene of Molybdenum, J. T. Ciszewski, B. Xie, C. Cao, A. L. Odom, Dalton Trans. 2003, 22, 4226.
Insertion of an Electron-rich Alkyne into a Molybdenum Amido Bond, E. Katayev, Y. Li, A. L. Odom, Chem. Commun. 2002, 8, 838.
Investigation of Transition Metal-Imido Bonding in M(NBut)2(dpma), J. T. Ciszewski, J. F. Harrison, A. L. Odom, Inorg. Chem. 2004, 43, 3605.
