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个人简介

Brandon was born (1976) in Golden Valley, Minnesota. In 1998 he received his B.S. degree in chemistry from the University of Minnesota–Twin Cities. During his undergraduate years he worked in the laboratories of Professor Thomas R. Hoye. In the fall of 1999 he entered the University of Texas at Austin and received his Ph.D. under the supervision of Professor Stephen F. Martin in 2004. His thesis work focused on the development of Rh(I)-catalyzed allylic alkylations and the application of rhodium-mediated cycloadditions and asymmetric cycloproplanations toward natural product synthesis. In December of 2004 he began his position as a National Institutes of Health Ruth L. Kirschstein postdoctoral fellow in the laboratories of Professor Barry M. Trost at Stanford University. During his time with Professor Trost he investigated a series of ruthenium- and palladium-catalyzed cross-couplings and cyclizations toward the synthesis of the marine macrolactone, miyakolide. In the fall of 2007 he began his independent career as an assistant professor of chemistry at the University of Notre Dame.

研究领域

Organic Chemistry

Our research program is focused on the development of new methods to enable unconventional bond formations in the synthesis of complex natural products and designed materials. Our main objective is to use new chemical constructs to design and synthesize improved chemotherapies for brain and CNS cancers, and materials that will ultimately lead to the reduction of atmospheric concentrations of anthropogenic CO2. Designing Brain and CNS Cancer Chemotherapeutics. We seek to addresses the issue of suitable brain and CNS drug treatment options by focusing on natural products with promising cytotoxicity that also display blood brain barrier (BBB) transcytosis properties. Specifically, the families of diarylheptanoids and glycosidic marine toxin natural products have captured our attention due to the potent anticancer activity exhibited by multiple members of each class. We are currently working toward the development of two new synthetic methods that will enable the efficient, and scalable construction of these natural products for the development of new CNS cancer chemotherapeutics. The first approach is based on the conceptual design of a tandem reaction sequence composed of mechanistically distinct transformations facilitated by a single catalyst to rapidly assemble all alkyl-substituted tertiary carbons centers. By exploiting aldehydes as traceless dielectrophilic entities, in conjunction with the bifunctional attributes of titanocene, we can construct multiple C–C and C–X bonds in a highly convergent fragment coupling. Our second area of methods development focuses on the formation of Csp2–N and Csp2–C bonds, which constitutes one of the most vibrant areas of research in synthetic organic chemistry today. Unfortunately, conventional multistep protocols involving organometallic reagents and transition metal complexes can complicate complex molecule synthesis. Our program is working toward providing a solution to this long-standing problem in organic synthesis through the development phosphorus-mediated C–C and C–N bond formations that ultimately circumvents the need for traditional organometallic or transition metal-based reagents. Innovating the Chemistry of Covalent Carbon Capture. Managing the impact of human activities on the concentration of CO2 in the atmosphere is the most far-reaching environmental challenge facing the world today. Carbon capture and separation is an integral part of our energy future, independent of its application to today’s coal-fired power plants. Our research program is working toward the development of a strategy to control atmospheric, anthropogenic CO2 concentrations through the design of energy efficient carbon capture and sequestration materials. Our ultimate goal is the development of a regenerative material that will undergo selective super-stoichiometric carbon capture with near-zero parasitic energy consumption. Recognizing that C–C and C–X chemical bonds are convenient media for energy storage, transport, and consumption, our efforts rely on the design and synthesis of functionalized N-heterocyclic anions and carbenes for energy efficient gas phase removal of CO2.

近期论文

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Meloche, J. L.; Ashfeld, B. L. “Development of a RhII-Catalyzed Formal [4+1]-Cycloaddition Toward Spirooxindole Pyrrolone Construction Employing Vinyl Isocyanates as 1,4-Dipoles” Angew. Chem. Int. Ed. 2017, Early View, DOI: 10.1002/anie.201701147. PDF Rodriguez, K. X.; Kaltwasser, N.; Toni, T. A.; Ashfeld, B. L. “Rearrangement of an Intermediate Cyclopropyl Ketene in a RhII-Catalyzed Formal [4+1]-Cycloaddition Employing Vinyl Ketenes as 1,4-Dipoles and Donor–Acceptor Metallocarbenes.” Org. Lett. 2017, ASAP, DOI: 10.1021/acs.orglett.7b00618. PDF Rodriguez, K. X.; Vail, J. D.; Ashfeld, B. L. “Phosphine-Mediated Stereoconvergent [4+1] Cycloannulation of 1,2-Dicarbonyls and ortho-Quinone Methides: A Multicomponent Assembly of 2,3-Dihydrobenzofurans.” Org. Lett., 2016, 18 (18), 4514-4517. PDF Higashi, D. L.; Biais, N.; Donahue, D. L.; Mayfield, J. A.; Tessier, C. R.; Rodriguez, K. X.; Ashfeld, B. L.; Luchetti, J.; Ploplis, V. A.; Castellino, F. J.; Lee, S. W. “Activation of Band 3 Mediates Group A Streptococcus Streptolysin S-Based β-Haemolysis.” Nat. Microbiol., 2016, 1 (2), 1-6. DOI:10.1038/nmicrobiol.2015.4. PDF White, E. E.; Rodriguez, K. X.; Ashfeld, B. L. “Stereochemical Implications in the Synthesis of 3,3´-Spirocyclopropyl Oxindoles from β-Aryl/Alkyl-Substituted Alkylidene Oxindoles.” Tetrahedron, 2015, 71 (35), 5765-5775. PDF Haugen, K. C.; Rodriguez, K. X.; Chavannavar, A. P.; Oliver, A. P.; Ashfeld, B. L. “Phosphine-Mediated Addition of 1,2-Dicarbonyls to Diazenes: An Umpolung Approach toward N-Acyl Hydrazone Synthesis.” Tetrahedron Lett. 2015, 56 (23), 3527-3530. PDF Gianino, J. B.; Campos, C. A.; Lepore, A. J.; Pinkerton, D. M.; Ashfeld, B. L. “Redox and Lewis Acid Relay Catalysis: A Titanocene/Zinc Catalytic Platform in the Development of Multicomponent Coupling Reactions.” J. Org. Chem. 2014, 79 (24), 12083-12095. PDF Chavannavar, A. P.; Oliver, A. G.; Ashfeld, B. L. “An Umpolung Approach Toward N-Aryl Nitrone Construction: Phosphine-Mediated Addition of 1,2-Dicarbonyls to Nitroso Electrophiles.” Chem. Commun. 2014, 50 (74), 10853-10856. PDF Meloche, J. L.; Vednor, P. T.; Gianino, J. B.; Oliver, A. G.; Ashfeld, B. L. “Titanocene-Catalyzed Metallation of Propargylic Acetates in Homopropargylic Alcohol Synthesis.” Tetrahedron Lett., 2014, 55 (36), 5025-5028. PDF Campos, C. A.; Gianino, J. B.; Bailey, B. J.; Baluyut, M. E.; Wiek, C.; Hanenberg, H.; Shannon, H.; Pollok, K. E.; Ashfeld, B. L. “Design, Synthesis, and Evaluation of Curcumin-Derived Arylheptanoids for Glioblastoma and Neuroblastoma Cytotoxicity.” Bioorg. Med. Chem. Lett. 2013, 23 (24), 6874-6878. PDF Vogt, M.; Wu, C.; Oliver, A. G.; Schneider, W. F.; Ashfeld, B. L. “Site Specific Carboxylation of Abnormal Anionic NHeterocyclic Dicarbenes with CO2.” Chem. Commun. 2013, 49 (98), 11527-11529. PDF Lee, D.; Zhang, C.; Wei, C.; Ashfeld, B. L.; Gao, H. “Developing Hierarchically Porous Polypyrrole Materials for Fast and Efficient CO2 Capture.” J. Mater. Chem. A. 2013, 1 (47), 14862-14867. PDF Fleury, L. M.; Wilson, E. E.; Vogt, M.; Fan, T. J.; Oliver, A. G.; Ashfeld, B. L. “An Amine-Free Approach Toward NToluenesulfonyl Amidine Construction: A Phosphite-Mediated Beckmann-Like Ligation of Oximes and Azides.” Angew. Chem. Int. Ed. 2013, 52 (44), 11589-11593. PDF Vogt, M.; Bennett, J. E.; Huang, Y.; Wu, C.; Brennecke, J. F.; Schneider, W. F.; Ashfeld, B. L. “Solid State Covalent Capture of CO2 Using N-Heterocyclic Carbenes.” Chem. Eur. J. 2013, 19 (34), 11134-11138. Lepore, A. J.; Pinkerton, D. M.; Ashfeld, B. L. “Relay Redox and Lewis Acid Catalysis in the Titanocene-Catalyzed Multicomponent Assembly of 1,5-Enynes.” Adv. Synth. Catal. 2013, 355, 1500-1504. PDF Campos, C. A.; Gianino, J. B.; Ashfeld, B. L. “Bifunctional Titanocene Catalysis in Multicomponent Couplings: A Convergent Assembly of β-Alkynyl Ketones.” Org. Lett. 2013, 15 (11), 2656-2659. PDF Meyer, C. J.; Vogt, M.; Catalino, J.; Ashfeld, B. L., “Synthesis of N-Heterocyclic Anionic Ionic Liquids from Functionalized Phosphonium Halides.” Synlett. 2013, 24, 1428-1432. PDF Fleury, L. M.; Kosal, A. D.; Masters, J. T.; Ashfeld, B. L., “Cooperative Phosphine and Titanocene Catalysis: Accelerated C–X Activation for Efficient Generation of Reactive Organometallics.” J. Org. Chem. 2013, 78 (2), 253-269. PDF Kosal, A. D.; Ashfeld, B. L. “N-(Benzyloxycarbonyloxy)-5-norbene-2,3-dicarboximide” Encyclopedia of Reagents for Organic Synthesis. 2013, DOI: 10.1002/047084289X.rn01521. Link Kosal, A. D.; Ashfeld, B. L. “N-(tert-Butyloxycarbonyloxy)-5-norbene-2,3-dicarboximide” Encyclopedia of Reagents for Organic Synthesis. 2013, DOI: 10.1002/047084289X.rn01520. Link

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