A5004988752- Innovative Microfluidic and Catalytic Techniques Innovation
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Chemical Synthesis and Analysis
- Catalytic Cross-Coupling Reactions
- Asymmetric Hydrogenation and Catalysis
- Microfluidic and Capillary Electrophoresis Applications
- Synthetic Organic Chemistry Methods
- HIV/AIDS drug development and treatment
- Organoboron and organosilicon chemistry
- Luminescence and Fluorescent Materials
- Synthesis and Catalytic Reactions
- Asymmetric Synthesis and Catalysis
- Nanomaterials for catalytic reactions
- Chemical Synthesis and Reactions
- Oxidative Organic Chemistry Reactions
- Molecular Sensors and Ion Detection
- American and British Literature Analysis
- Carbohydrate Chemistry and Synthesis
- N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
- Click Chemistry and Applications
- Chemistry and Chemical Engineering
- Advanced Polymer Synthesis and Characterization
- Cyclopropane Reaction Mechanisms
- Diet, Metabolism, and Disease
Virginia Commonwealth University
2013-2022
University of Richmond
2021
Florida State University
2008-2017
Tallahassee Orthopedic Clinic
2014-2017
Max Planck Institute of Colloids and Interfaces
2012-2015
Max Planck Society
2013-2014
Janssen (Belgium)
2014
University of Applied Sciences Potsdam
2014
Cornell University
2003-2013
Pusan National University
2012-2013
The synthesis of complex molecules requires control over both chemical reactivity and reaction conditions. While drives the majority discovery, advances in condition have accelerated method development/discovery. Recent tools include automated synthesizers flow reactors. In this Synopsis, we describe how reactors enabled our groups areas single-stage reactions, materials synthesis, multistep reactions. each section, detail lessons learned propose future directions.
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSignal Amplification of a "Turn-On" Sensor: Harvesting the Light Captured by Conjugated PolymerD. Tyler McQuade, Ashleigh H. Hegedus, and Timothy M. SwagerView Author Information Department Chemistry Massachusetts Institute Technology Cambridge, 02139 Cite this: J. Am. Chem. Soc. 2000, 122, 49, 12389–12390Publication Date (Web):November 23, 2000Publication History Received5 September 2000Published online23 November inissue 1 December...
[reaction: see text] On the basis of reaction rate data, we have proposed a new mechanism for Baylis-Hillman involving formation hemiacetal intermediate. We determined that rate-determining step is second order in aldehyde and first DABCO acrylate. shown this general to aryl aldehydes under polar, nonpolar, protic conditions using both data two isotope effect experiments.
Using reaction rate data collected in aprotic solvents, we have determined that the Baylis−Hillman rate-determining step is second order aldehyde and first DABCO acrylate. On basis of these data, proposed a new mechanism involving hemiacetal intermediate. The was then supported using two different kinetic isotope experiments.
A simple approach to a microfluidic device is described. The composed of flexible tubing and needle inserted orthogonal the long axis tubing. This design well suited creating oil-water interfaces allowing formation laminar flows monodisperse emulsions. system characterized by mapping phases observed as function organic phase flow Reynolds number. In addition, allows interfacial polymerization reactions capture low coefficient variation capsules. shell structure surface are examined scanning...
We present a 6-NHC−Cu(I) complex that provides α-substituted allylboronates using allylic aryl ether substrates. The method was discovered by comparison of the chemoselectivities exhibited complexes 1a, 1b, 2, and 3. observed 1a preferentially reacts with electron-rich alkenes over electron-deficient alkenes. Development an asymmetric revealed 1b both E Z isomers to provide same absolute configuration without showing E−Z isomerization. This stereoconvergent reaction occurs high yields (av...
A chiral 6-membered annulated N-heterocyclic (6-NHC) copper complex that catalyzes β-borylations with high yield and enantioselectivity was developed. The 6-NHC is easy to prepare on the gram scale very active, showing 10 000 turnovers at 0.01 mol % of catalyst without significant decrease useful reaction rates.
Solids go with the flow: A monodisperse flow in a microreactor provides an efficient method for keeping solid products away from channel walls. The use of carrier phase, such as mineral oil, hexane, or toluene, enables solids to be synthesized without clogging reactor channels. Further injection points can added perform multistep syntheses (see picture).
Abstract Primary and secondary amines can be rapidly quantitatively oxidized to the corresponding imines by singlet oxygen. This reactive form of oxygen was produced using a variable‐temperature continuous‐flow LED‐photoreactor with catalytic amount tetraphenylporphyrin as sensitizer. α‐Aminonitriles were obtained in good excellent yields when trimethylsilyl cyanide served an situ imine trap. At 25°C, primary found undergo oxidative coupling prior addition yielded α‐aminonitriles....
Described is a continuous, divergent synthesis system which coupled to continuous purification and capable of producing four anti-malarial APIs. The comprised three linked reaction modules for photooxidation/cyclization, reduction, derivatization. A fourth module couples the crude stream with yield pure API.
Abstract Efavirenz is an essential medicine for the treatment of HIV, which still inaccessible to millions people worldwide. A novel, semi‐continuous process provides rac ‐Efavirenz with overall yield 45 %. This streamlined proof‐of‐principle synthesis relies on efficient copper‐catalyzed formation aryl isocyanate and a subsequent intramolecular cyclization install carbamate core in one step. The three‐step method represents shortest this life‐saving drug date.
Two polymer chains are forced into contact by 2:1 sandwich complex formation between K+ ions and [15]crown-5 groups. By controlling the steric bulk of side groups repeating units distance on main chain (see picture) interpolymer interactions induced can be tuned. Four poly(p-phenylene ethynylene)s with were prepared, two which designed to function as potassium sensory materials.
We present a new microencapsulated catalyst and report its use in tandem multicatalyst reaction. Using an encapsulation technique, we developed active, site-isolated amine that is capable of catalyzing the addition nitromethane to aldehyde. When second Lewis acid added, nitroalkene intermediate trapped converted corresponding Michael adduct. show if not encapsulated, two catalysts cannot function together. Moreover, reactions are performed sequence rather than tandem, first reaction results...
In this paper, we describe the development and application of a multistep one-pot reaction that is made possible by site isolation two otherwise incompatible catalysts. We prepared microencapsulated amine catalyst interfacial polymerization used it in conjunction with nickel-based for transformation an aldehyde to Michael adduct via nitroalkene intermediate. The amine-catalyzed conversion was found proceed through imine rather than nitroalcohol. Kinetic studies indicated first order both...
Abstract The union between polymer science and microfluidics is reviewed. Fluids in microreactors allow the synthesis of a wide range polymeric materials with unique properties. We begin by discussing important fluid dynamics that dominate behavior fluids on micrometer scale. then progress through comprehensive analysis synthesized to date. This highlight concludes an overview methods used make microreactors. enthusiastically endorse as powerful approach making controlled properties,...
Ylidenemalononitrile enamines undergo rapid amine exchange followed by a cyclization with primary amines to yield fluorescent products emission intensities as high 900 times greater than the starting materials. After identifying species X-ray crystallography, we demonstrate that rate of is substrate dependent and simple structural variation fluorescence can be tuned over entire visible spectrum. We further their potential application in biomolecule labeling.
The catalytic regioselective hydroboration of propargylic alcohols and ethers was investigated using NHC-CuCl. We observe that different NHC-CuCl complexes catalyze hydroborations substrates with opposite regioselectivity. A 6-NHC-CuCl complex provides α-selectivity whereas β-selectivity is achieved a 5-NHC-CuCl complex. reaction tolerates wide range functional groups.
Abstract The Negishi cross‐coupling is a powerful CC bond forming reaction. method less commonly used relative to other methods in part due lack of availability organozinc species. While species can be prepared, problems with reproducibility and handling these sensitive complicate reactions. Herein, we describe the continuous formation, using an activated packed‐bed metallic zinc, subsequent use halides. We demonstrate that single column zinc provide excellent yields halides they downstream...
The viability of conjugated polymer thin film electrooptical devices and sensors depends strongly on high quantum efficiency films with excellent charge exciton mobilities.1,2 brightness electroluminescent the transport emission efficiency, energy migration to low sites can provide necessary wavelength shifts for lasing.3 A highly sensitive specific sensory device requires that a recognition event be coupled an amplification mechanism. We are particularly interested in exploiting collective...