Research

Research in the Blum Group focuses on the development of new catalysts and metal-mediated reactions with applications in organic synthesis. We are also developing single-molecule techniques to image catalytic reactions at individual transition metal centers. These single-molecule techniques are part of a big-picture, ground-breaking project to change the way chemists think about studying chemical reaction mechanisms: by actually watching reactions live, one molecule at a time. Ultimately, we are interested in learning about the reactivity of transition metals such that those lessons can be applied broadly to the development of new methods. These studies provide an excellent platform for testing mechanistic hypotheses and for building new fundamental understanding of metal-based reactivity.

Publications

Canham, S. M.; Bass, J. Y.; Navarro, O.; Lim, S. G.; Das, N.; Blum, S. A. "Toward the Single-Molecule Investigation of Organometallic Reaction Mechanisms: Single-Molecule Imaging of Fluorophore-Tagged Palladium(II) Complexes" Organometallics 2008, 27, 2172. [Link]

Highlighted in Chem. & Eng. News 2008, 86, 43. [Link]

We report the first example of single-molecule imaging of fluorophore-tagged transition metal complexes outside of biological systems: the single-molecule imaging of individual palladium(II) complexes. The requisite high-quantum-yield BODIPY fluorophore tags are synthesized and shown to act as spectators when bound to metal complexes. These combined experimental results lay the fundamental groundwork for studying organometallic reaction chemistry at the single-molecule level using fluorophore tags.

Shi, Y.; Peterson, S. M.; Haberaecker, W. W., III; Blum, S. A. "Alkynes as Stille Reaction Pseudohalides: Synthesis of Tri- and Tetra-Substituted Olefins." J. Am. Chem. Soc. 2008, 130, 2168. [Link]

Highlighted in Angew. Chem., Int. Ed. 2008, 47, 5703. [Link]

A Stille-type reaction that employs alkynes as pseudohalides provides access to the catalytic chemistry of palladium-carbon -bonds starting from -systems. The synthesis of a variety of tri- and tetra-substituted olefins by addition of sp²- and sp-hybridized stannanes across mono- and diester alkynes was accomplished with complete regioselectivity and high stereoselectivity. The reaction is proposed to proceed via a bimetallic mechanism where the Lewis acidic Au(I) activates the alkyne toward oxidative addition across Pd(0).



			Research Research in the Blum Group focuses on the development of new catalysts and metal-mediated reactions with applications in organic synthesis. We are also developing single-molecule techniques to image catalytic reactions at individual transition metal centers. These single-molecule techniques are part of a big-picture, ground-breaking project to change the way chemists think about studying chemical reaction mechanisms: by actually watching reactions live, one molecule at a time. Ultimately, we are interested in learning about the reactivity of transition metals such that those lessons can be applied broadly to the development of new methods. These studies provide an excellent platform for testing mechanistic hypotheses and for building new fundamental understanding of metal-based reactivity. Publications Canham, S. M.; Bass, J. Y.; Navarro, O.; Lim, S. G.; Das, N.; Blum, S. A. "Toward the Single-Molecule Investigation of Organometallic Reaction Mechanisms: Single-Molecule Imaging of Fluorophore-Tagged Palladium(II) Complexes" Organometallics 2008, 27, 2172. [Link] Highlighted in Chem. & Eng. News 2008, 86, 43. [Link] We report the first example of single-molecule imaging of fluorophore-tagged transition metal complexes outside of biological systems: the single-molecule imaging of individual palladium(II) complexes. The requisite high-quantum-yield BODIPY fluorophore tags are synthesized and shown to act as spectators when bound to metal complexes. These combined experimental results lay the fundamental groundwork for studying organometallic reaction chemistry at the single-molecule level using fluorophore tags. Shi, Y.; Peterson, S. M.; Haberaecker, W. W., III; Blum, S. A. "Alkynes as Stille Reaction Pseudohalides: Synthesis of Tri- and Tetra-Substituted Olefins." J. Am. Chem. Soc. 2008, 130, 2168. [Link] Highlighted in Angew. Chem., Int. Ed. 2008, 47, 5703. [Link] A Stille-type reaction that employs alkynes as pseudohalides provides access to the catalytic chemistry of palladium-carbon -bonds starting from -systems. The synthesis of a variety of tri- and tetra-substituted olefins by addition of sp²- and sp-hybridized stannanes across mono- and diester alkynes was accomplished with complete regioselectivity and high stereoselectivity. The reaction is proposed to proceed via a bimetallic mechanism where the Lewis acidic Au(I) activates the alkyne toward oxidative addition across Pd(0).