A5085302439- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Korean Peninsula Historical and Political Studies
- Asymmetric Synthesis and Catalysis
- Synthetic Organic Chemistry Methods
- Chemical synthesis and alkaloids
- Oxidative Organic Chemistry Reactions
- Catalytic C–H Functionalization Methods
- Traditional and Medicinal Uses of Annonaceae
- Marine Sponges and Natural Products
- Microbial Natural Products and Biosynthesis
- Cyclopropane Reaction Mechanisms
- Chemical Synthesis and Reactions
- Advanced Synthetic Organic Chemistry
- Chemical Synthesis and Analysis
- Crystallography and molecular interactions
- Synthesis and Catalytic Reactions
- Carbohydrate Chemistry and Synthesis
- Bioactive natural compounds
- Alkaloids: synthesis and pharmacology
- Catalytic Cross-Coupling Reactions
- Computational Drug Discovery Methods
- Enzyme Production and Characterization
- International Relations and Foreign Policy
- Sulfur-Based Synthesis Techniques
University of Chicago
2016-2025
Indiana University – Purdue University Indianapolis
2024
Indiana University School of Medicine
2023-2024
Ligand Pharmaceuticals (United States)
2023
Indiana University
2023
Columbia University
2011-2022
University of California, Merced
2022
University of California, Irvine
2022
Western Washington University
2022
Northwestern University
2022
Cascade reactions and biomimetic strategies are being increasingly applied to the construction of natural designed molecules. Such processes, in which ideally a single event triggers conversion starting material product then becomes substrate for next reaction until termination leads stable final product, highly desirable not only due their elegance, but also because efficiency economy terms reagent consumption purification. Often, these multistep, one-pot procedures accompanied by dramatic...
The pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) continues to expand. Papain-like protease (PLpro) is one of two SARS-CoV-2 proteases potentially targetable with antivirals. PLpro an attractive target because it plays essential role in cleavage and maturation viral polyproteins, assembly the replicase-transcriptase complex, disruption host responses. We report a substantive body structural, biochemical, virus replication studies that identify several...
In den letzten Jahrzehnten hat wohl keine andere Reaktion das Forschungsgebiet der Totalsynthese mehr geprägt als die Diels-Alder-Reaktion. Mit einer Vielzahl von Anwendungen dieser großartigen pericyclischen Reaktion, oftmals entscheidendes Element eleganten Kaskadenreaktion zur Herstellung komplexer Molekülstrukturen, ermöglichte Diels-Alder-Cycloaddition Lösung Reihe unterschiedlicher, Natur in Form Naturstoffen gestellter Syntheseprobleme. Zur Feier des hundertjährigen Jubiläums Alders...
Although biomimetic approaches have proven capable of converting resveratrol (1) concurrently into many the more complex oligomers produced by plants throughout world (such as 2−10), methods to access single members family far difficult identify. Herein is described a strategy-level solution based on use common building block, one distinct from Nature's starting material, that can participate in variety highly selective, reagent-controlled reaction cascades. These endeavors led controlled...
Although there are many reagent combinations that can initiate polyene cyclizations, simple electrophilic halogen sources have not yet proven broadly effective as promoters of such processes. Herein is described a readily prepared and stable class reagents capable effecting transformations for wide range electron-rich -deficient terpenes derived from geraniol, farnesol, nerol, thereby enabling the synthesis diverse array complex chlorine-, bromine-, iodine-containing polycyclic frameworks....
With the addition of a tenth ring, exchange an oxygen atom for nitrogen in heart molecule, and different terminal residue, revised architecture diazonamide A (1) provided even more challenging molecular puzzle chemical synthesis than its predecessor. In this article, we detail first successful total A, endeavor which not only verified proper connectivities established stereochemistry previously unassignable C-37 chiral center, but also was attended by development several new synthetic...
The uniquely woven, highly strained molecular architecture and the potent antitumor activity of diazonamide A (1) make this natural product an attractive synthetic target. key steps in total synthesis 1 include a novel SmI2-induced ring-closing cascade sequence unusual oxidation indoline to oxindole presence Pd(OH)2/C.
The napyradiomycins are an intriguing family of halogenated natural products with activity against several tumor cell lines as well some the worst bacterial strains known to humanity, including methicillin-resistant Staphylococcus aureas and vancomycin-resistant Enterococcus faecium. This communication delineates first asymmetric total synthesis (-)-napyradiomycin A1 by a strategy that features two-step flaviolin, highly halogenation simple alkene, Johnson-Claisen rearrangement generates...
Despite the attention paid to resveratrol (1) owing its potent biological activity, little effort has been devoted studying resveratrol-based oligomers (such as 2–4). The first general synthetic approach is outlined for accessing carbogenic diversity possessed by this family of compounds. Supporting information article available on WWW under http://www.wiley-vch.de/contents/jc_2002/2007/z703333_s.pdf or from author. Please note: publisher not responsible content functionality any supporting...
It's all about reactivity: Although bromonium-induced cation–π cyclizations are commonly utilized by nature to fashion six-membered rings from a diverse set of polyene precursors, no general laboratory method exists that can achieve the same breadth substrate scope. An easily synthesized and handled reagent is described (see scheme) capable directly, broadly, rapidly effecting such reactions in good yield with variety geraniol, farnesol, nerol derivatives.
The structurally unique akuammiline alkaloid (+)-scholarisine A was synthesized in 14 steps from a known enone (15 commercial materials) through route empowered by C–H arylation reaction to forge its polycyclic core. Additional key include pyrone Diels–Alder and radical cyclization/Keck allylation fashion the core cage polycycle one of molecule's quaternary centers, as well use carefully positioned pendant hydroxyl group facilitate chemoselective reduction an extremely unreactive lactam...
Understanding the mechanisms of charge transport in batteries is important for rational design new electrolyte formulations. Persistent questions about ion battery electrolytes are often framed terms vehicular diffusion by persistent ion-solvent complexes versus structural through breaking and reformation contacts, i.e., solvent exchange events. Ultrafast two-dimensional (2D) IR spectroscopy can probe processes directly via evolution cross-peaks on picosecond time scales. However,...
ABSTRACT Gap junctions provide direct intercellular communication by linking adjacent cells with aqueous pores permeable to molecules up 1 kDa in molecular mass and 8-14 Å diameter. The identification of over a dozen connexins the mammalian gap junction family has stimulated interest functional significance this diversity, including possibility selectivity for permeants as seen other channel classes. Here we present quantitative comparison permeabilities different expressed both HeLa...
Ever since its discovery in 1991, diazonamide A (1) has been eyed by synthetic chemists as a potential target because of puzzling molecular architecture and potent biological activity. The race to synthesize this intriguing natural product was further complicated at the end last year when synthesis completed only prove that originally proposed structure error. new structural assignment (2) required retooling strategies toward target. total now achieved confirming newly structure. In Fenical...
As an especially unique target for chemical synthesis, diazonamide A has the potential to be constructed through a plethora of synthetic routes, each attended by different challenges and opportunities discovery. In this article, we detail our second total synthesis sequence entirely distinct from that employed in first campaign, one whose success required development several special strategies tactics. We also disclose complete studies regarding biology its structural congeners, more fully...
Abstract Im Laufe der vergangenen 50 Jahre hat hinsichtlich Aufklärung Strukturen unbekannter Naturstoffe eine gewaltige Umwälzung stattgefunden. In ersten Hälfte des Jahrhunderts war man fast ausschließlich auf die Kunst chemischen Synthese angewiesen, um in jahrelanger Arbeit – hauptsächlich mithilfe von Abbaureaktionen und Derivatisierungen Hypothesen zur Struktur zu überprüfen. Heute stehen mit multidimensionalen NMR‐Spektroskopie, hochauflösenden Massenspektrometrie nicht zuletzt...
A polycyclic collapse: Use of a carefully designed acyclic intermediate participated in cascade reaction that formed the entire core polyketide-derived dalesconols single flask (see scheme). number additional and controlled synthetic operations completed an expeditious synthesis both these highly bioactive natural products as well structural congenors.
A unique procedure to effect a ring-expanding bromoetherification process is described, wherein tetrahydrofurans and tetrahydropyrans are smoothly transformed into 8- 9-membered bromoethers in regio- stereocontrolled manner through the use of BDSB (bromodiethylsulfonium bromopentachloroantimonate). These products resemble cores Laurencia C15 acetogenins. In light generality effectiveness approach, this work provides strategy for their laboratory preparation may implicate possible...