A5037348586- Oxidative Organic Chemistry Reactions
- Synthesis and Catalytic Reactions
- Catalytic C–H Functionalization Methods
- Asymmetric Hydrogenation and Catalysis
- Carbohydrate Chemistry and Synthesis
- Chemical Synthesis and Analysis
- Radical Photochemical Reactions
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Asymmetric Synthesis and Catalysis
- Glycosylation and Glycoproteins Research
- Enzyme Production and Characterization
- Metal-Catalyzed Oxygenation Mechanisms
- CO2 Reduction Techniques and Catalysts
- Astrophysics and Star Formation Studies
- Catalysis for Biomass Conversion
- Molecular Spectroscopy and Structure
- Synthetic Organic Chemistry Methods
- Atmospheric Ozone and Climate
- Beetle Biology and Toxicology Studies
- Synthesis of heterocyclic compounds
- Polyoxometalates: Synthesis and Applications
- Polyamine Metabolism and Applications
- Catalysis and Oxidation Reactions
- Cyclopropane Reaction Mechanisms
Massachusetts Institute of Technology
2019-2024
Harvard University
2018-2022
Harvard University Press
2022
Physical Sciences (United States)
2022
University of Wisconsin–Madison
2011-2019
University of Kentucky
2010-2015
The selective oxidation of C-H bonds and the use O(2) as a stoichiometric oxidant represent two prominent challenges in organic chemistry. Copper(II) is versatile oxidant, capable promoting wide range oxidative coupling reactions initiated by single-electron transfer (SET) from electron-rich molecules. Many these can be rendered catalytic Cu employing molecular oxygen to regenerate active copper(II) catalyst. Meanwhile, numerous other recently reported Cu-catalyzed feature substrates that...
Abstract Die selektive Oxidation von C‐H‐Bindungen und der Einsatz O 2 als stöchiometrisches Oxidationsmittel stellen zwei wesentliche Herausforderungen in organischen Chemie dar. Kupfer(II) ist ein vielseitiges für verschiedene oxidative Kupplungen, die durch Einelektronen‐Transfer (SET) elektronenreichen Molekülen ausgelöst werden. Viele dieser Reaktionen können mit Kupfer katalytisch durchgeführt werden, wenn molekularer Sauerstoff eingesetzt wird, um den aktiven Kupfer(II)‐Katalysator zu...
Copper amine oxidases are a family of enzymes with quinone cofactors that oxidize primary amines to aldehydes. The native mechanism proceeds via an iminoquinone intermediate promotes high selectivity for reactions amines, thereby constraining the scope potential biomimetic synthetic applications. Here we report novel bioinspired catalyst system consisting 1,10-phenanthroline-5,6-dione/ZnI2 bypasses these constraints abiological pathway involving hemiaminal intermediate. Efficient aerobic...
Quinolines are common pharmacophores present in numerous FDA-approved pharmaceuticals and other bioactive compounds. Here, we report the design development of new o-quinone-based catalysts for oxidative dehydrogenation tetrahydroquinolines to afford quinolines. Use a Co(salophen) cocatalyst allows reaction proceed efficiently with ambient air at room temperature. The utility catalytic method is demonstrated preparation number medicinally relevant
Biomimetic aerobic oxidation of primary benzylic amines has been achieved by using a quinone catalyst. Excellent selectivity is observed for primary, unbranched relative to secondary/tertiary amines, branched and aliphatic amines. The exquisite enables oxidative self-sorting within dynamic mixtures imines afford high yields cross-coupled imine products.
Here, we report the selective, catalytic isomerization of
The positional isomerization of C═C double bonds is a powerful strategy for the interconversion alkene regioisomers. However, existing methods provide access to thermodynamically more stable isomers from less starting materials. Here, we report discovery dual catalyst system that promotes contra-thermodynamic under photochemical irradiation, providing terminal directly conjugated, internal utility method demonstrated in deconjugation diverse electron-rich/electron-poor alkenes and through...
The stereoselective synthesis of complex targets requires the precise orchestration chemical transformations that simultaneously establish connectivity and spatial orientation desired bonds. In this work, we describe a complementary paradigm for chiral molecules their isomers, which tunes three-dimensional structure molecule at late stage. Key to success strategy is development mild highly general photocatalytic method composed decatungstate polyanion disulfide cocatalysts, enable...
Radical-mediated transformations have emerged as powerful methods for the synthesis of rare and unnatural branched, deoxygenated, isomeric sugars. Here, we describe a radical-mediated axial-to-equatorial alcohol epimerization method to transform abundant glycans into isomers. The delivers highly predictable selective reaction outcomes that are complementary other sugar isomerization methods. synthetic utility isomer interconversion is showcased through expedient glycan synthesis, including...
Polycyclic aromatic hydrocarbons (PAHs) are organic molecules containing adjacent rings. Infrared emission bands show that PAHs abundant in space, but only a few specific have been detected the interstellar medium. We 1-cyanopyrene, cyano-substituted derivative of related four-ring PAH pyrene, radio observations dense cloud TMC-1, using Green Bank Telescope. The measured column density 1-cyanopyrene is <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"...
Abstract Chinone sind gebräuchliche, stöchiometrisch eingesetzte Reagentien in der organischen Chemie. para‐Chinone mit hohem Reduktionspotential wie DDQ und Chloranil werden verbreitet angewendet fördern normalerweise die Hydridabstraktion. In den letzten Jahren wurden viele katalytische Anwendungen dieser Methoden entwickelt, wobei das oxidierte Chinon situ mithilfe von Übergangsmetallen, O 2 oder Elektrochemie regeneriert wird. Ergänzende Studien haben zur Entdeckung einer anderen Klasse...
The selective manipulation of carbohydrate scaffolds is challenging due to the presence multiple, nearly chemically indistinguishable O-H and C-H bonds. As a result, protecting-group-based synthetic strategies are typically necessary for modification. Here we report concise semisynthetic strategy access diverse 2- 4-deoxygenated carbohydrates without relying on exhaustive use protecting groups achieve site-selective reaction outcomes. Our approach leverages Mn2+-promoted redox isomerization...
Polycyclic aromatic hydrocarbons (PAHs) are among the most widespread compounds in universe, accounting for up to ~25% of all interstellar carbon. Since unsubstituted PAHs do not possess permanent electric dipole moments, they invisible radio astronomy. Constraining their abundances relies on detection polar chemical proxies, such as nitriles. Here we report 2-cyanopyrene and 4-cyanopyrene, isomers recently detected 1-cyanopyrene. We find that these present an abundance ratio ~2:1:2, which...
The copper(II)-mediated oxidative cyclization of enamides to oxazoles is reported. A range 2,5-disubstituted were prepared in moderate good yields two steps from simple amide and alkyne precursors.
A transition-metal/quinone complex, [Ru(phd)3]2+ (phd = 1,10-phenanthroline-5,6-dione), is shown to be effective for aerobic dehydrogenation of 3° indolines the corresponding indoles. The results show how low potential quinones may tailored provide a catalytic alternative stoichiometric DDQ, due their ability mediate efficient substrate while also being compatible with facile reoxidation by O2. utility method demonstrated in synthesis key intermediates pharmaceutically important molecules.
Stereochemical editing strategies have recently enabled the transformation of readily accessible substrates into rare and valuable products. Typically, site selectivity is achieved by minimizing kinetic complexity using protecting groups to suppress reactivity at undesired sites (substrate control) or catalysts with tailored shapes drive desired (catalyst control). We propose "network control," a contrasting paradigm that exploits hidden interactions between rate constants greatly amplify...
Small, strained ring systems are important pharmacophores in medicinal chemistry and versatile intermediates organic synthesis. However, the kinetic thermodynamic instability of many molecules renders them challenging to prepare. Here, we report a strain-inducing positional alkene isomerization reaction that provides mild selective access cyclobutene building blocks from readily obtained cyclobutylidene precursors. This endergonic relies on sequential synergistic action decatungstate...
Alternative pre-mRNA splicing is a central element of eukaryotic gene expression. Its deregulation can lead to disease, and methods change splice site selection are developed as potential therapies. Spinal muscular atrophy caused by the loss SMN1 (survival motoneuron 1) gene. A therapeutic avenue for spinal treatment promote exon 7 inclusion almost identical SMN2 2) The factor tra2-beta1 promotes this antagonized protein phosphatase (PP) 1. To identify new compounds that inclusion, we...