Education & Certifications
B.S., University of Illinois at Urbana-Champaign, Chemistry (2010)
B.S., University of Illinois at Urbana-Champaign, Engineering Physis (2010)
Matthew Kanan, Doctoral Dissertation Advisor (AC)
Martin D. Burke, Graham R. Dick, David M. Knapp, Eric P. Gillis, Jenna A. Klubnick. "United States Patent 8,557,980 Methods for forming protected organoboronic acids", The Board Of Trustees Of The University Of Illinois, Oct 15, 2013
Carbon dioxide utilization via carbonate-promoted C-H carboxylation
2016; 531 (7593): 215-?
Using carbon dioxide (CO2) as a feedstock for commodity synthesis is an attractive means of reducing greenhouse gas emissions and a possible stepping-stone towards renewable synthetic fuels. A major impediment to synthesizing compounds from CO2 is the difficulty of forming carbon-carbon (C-C) bonds efficiently: although CO2 reacts readily with carbon-centred nucleophiles, generating these intermediates requires high-energy reagents (such as highly reducing metals or strong organic bases), carbon-heteroatom bonds or relatively acidic carbon-hydrogen (C-H) bonds. These requirements negate the environmental benefit of using CO2 as a substrate and limit the chemistry to low-volume targets. Here we show that intermediate-temperature (200 to 350 degrees Celsius) molten salts containing caesium or potassium cations enable carbonate ions (CO3(2-)) to deprotonate very weakly acidic C-H bonds (pKa > 40), generating carbon-centred nucleophiles that react with CO2 to form carboxylates. To illustrate a potential application, we use C-H carboxylation followed by protonation to convert 2-furoic acid into furan-2,5-dicarboxylic acid (FDCA)--a highly desirable bio-based feedstock with numerous applications, including the synthesis of polyethylene furandicarboxylate (PEF), which is a potential large-scale substitute for petroleum-derived polyethylene terephthalate (PET). Since 2-furoic acid can readily be made from lignocellulose, CO3(2-)-promoted C-H carboxylation thus reveals a way to transform inedible biomass and CO2 into a valuable feedstock chemical. Our results provide a new strategy for using CO2 in the synthesis of multi-carbon compounds.
View details for DOI 10.1038/nature17185
View details for Web of Science ID 000371665100037
View details for PubMedID 26961655
Interfacial Electric Field Effects on a Carbene Reaction Catalyzed by Rh Porphyrins
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
2013; 135 (30): 11257-11265
An intramolecular reaction catalyzed by Rh porphyrins was studied in the presence of interfacial electric fields. 1-Diazo-3,3-dimethyl-5-phenylhex-5-en-2-one (2) reacts with Rh porphyrins via a putative carbenoid intermediate to form cyclopropanation product 3,3-dimethyl-5-phenylbicyclo[3.1.0]hexan-2-one (3) and insertion product 3,3-dimethyl-2,3-dihydro-[1,1'-biphenyl]-4(1H)-one (4). To study this reaction in the presence of an interfacial electric field, Si electrodes coated with thin films of insulating dielectric layers were used as the opposing walls of a reaction vessel, and Rh porphyrin catalysts were localized to the dielectric-electrolyte interface. The charge density was varied at the interface by changing the voltage across the two electrodes. The product ratio was analyzed as a function of the applied voltage and the surface chemistry of the dielectric layer. In the absence of an applied voltage, the ratio of 3:4 was approximately 10:1. With a TiO2 surface, application of a voltage induced a Rh porphyrin-TiO2 interaction that resulted in an increase in the 3:4 ratio to a maximum in which 4 was nearly completely suppressed (>100:1). With an Al2O3 surface or an alkylphosphonate-coated surface, the voltage caused a decrease in the 3:4 ratio, with a maximum effect of lowering the ratio to 1:2. The voltage-induced decrease in the 3:4 ratio in the absence of TiO2 was consistent with a field-dipole effect that changed the difference in activation energies for the product-determining step to favor product 4. Effects were observed for porphyrin catalysts localized to the electrode-electrolyte interface either through covalent attachment or surface adsorption, enabling the selectivity to be controlled with unfunctionalized Rh porphyrins. The magnitude of the selectivity change was limited by the maximum interfacial charge density that could be attained before dielectric breakdown.
View details for DOI 10.1021/ja404394z
View details for Web of Science ID 000322752900058
View details for PubMedID 23837635
A General Solution for the 2-Pyridyl Problem
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
2012; 51 (11): 2667-2672
Problem solved: an air-stable 2-pyridyl borane that can effectively couple to a wide range of aryl and heteroaryl halides and pseudohalides has evaded the synthesis community for decades. The discovery that Cu(DEA)(2) powerfully enables palladium-mediated cross-couplings with air-stable boronates 1 has finally provided a general solution to this problem. DEA=diethanolamine, DMF=N,N'-dimethylformamide, Tf=trifluoromethanesulfonyl.
View details for DOI 10.1002/anie.201108608
View details for Web of Science ID 000301173800023
View details for PubMedID 22287537
General Method for Synthesis of 2-Heterocyclic N-Methyliminodiacetic Acid Boronates
2010; 12 (10): 2314-2317
A wide range of 2-pyridyl and other difficult-to-access heterocyclic N-methyliminodiacetic acid boronates can be readily prepared from the corresponding bromides via a new method involving direct transligation of 2-heterocyclic trialkoxyborate salts with N-methyliminodiacetic acid (MIDA) at elevated temperatures.
View details for DOI 10.1021/ol100671v
View details for Web of Science ID 000277531000037
View details for PubMedID 20465293