A5013585464- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Crystallography and molecular interactions
- Asymmetric Hydrogenation and Catalysis
- Asymmetric Synthesis and Catalysis
- Catalytic C–H Functionalization Methods
- Cyclopropane Reaction Mechanisms
- Synthetic Organic Chemistry Methods
- Zeolite Catalysis and Synthesis
- Crystal Structures and Properties
- Chemical Synthesis and Characterization
- Chemical Synthesis and Analysis
- Metal-Organic Frameworks: Synthesis and Applications
- Mesoporous Materials and Catalysis
- Radical Photochemical Reactions
- Synthesis and Catalytic Reactions
- Fullerene Chemistry and Applications
- Superconducting Materials and Applications
- Molecular Junctions and Nanostructures
- Synthesis and Properties of Aromatic Compounds
- Magnetism in coordination complexes
- Molecular Sensors and Ion Detection
- Inorganic Fluorides and Related Compounds
- Catalytic Alkyne Reactions
- Chemical synthesis and alkaloids
University of Oxford
2016-2025
University of Connecticut
2024
Vrije Universiteit Amsterdam
2021
Science Oxford
2017-2021
Oxfam
2014-2021
Oxford Research Group
2012-2021
Polish Academy of Sciences
2020
Institute of Organic Chemistry
2020
Institute of Crystallography
2019
Morgan, Lewis & Bockius (United States)
2019
We report the first use of solution-phase halogen bonding to control and facilitate assembly an interlocked structure through bromide anion-templated formation a rotaxane based upon iodotriazolium axle. The incorporation atom into host cavity dramatically improves anion-recognition capabilities receptor, giving unusual iodide selectivity in competitive aqueous medium.
Electron-deficient heavy chalcogen atoms contain Lewis acidic σ-holes which are able to form attractive supramolecular interactions, known as bonding (ChB), with bases. However, their potential in solution-phase anion binding applications is only just beginning be realized simple acyclic systems. Herein, we explore the 5-(methylchalcogeno)-1,2,3-triazole (chalcogen = Se, Te) motif a novel ChB donor for binding. Other than being chemically robust enough incorporated into macrocyclic...
Common anionic nucleophiles such as those derived from inorganic salts have not been used for enantioselective catalysis because of their insolubility. Here, we report that merging hydrogen bonding and phase-transfer provides an effective mode activation are insoluble in organic solvents. This catalytic manifold relies on complexation to render soluble reactive, while simultaneously inducing asymmetry the ensuing transformation. We demonstrate concept using a chiral bis-urea catalyst form...
Synthetic carbon allotropes such as graphene1, nanotubes2 and fullerenes3 have revolutionized materials science led to new technologies. Many hypothetical been discussed4, but few studied experimentally. Recently, unconventional synthetic strategies dynamic covalent chemistry5 on-surface synthesis6 used create forms of carbon, including γ-graphyne7, fullerene polymers8, biphenylene networks9 cyclocarbons10,11. Cyclo[N]carbons are molecular rings consisting N atoms12,13; the three that...
Molecules that contain a stereogenic phosphorus atom are crucial to medicine, agrochemistry and catalysis. While methods available for the selective construction of various chiral organophosphorus compounds, catalytic enantioselective approaches their synthesis far less common. Given vastness possible substituent combinations around atom, protocols preparation should also be divergent, providing facile access not only one but many classes compounds. Here we introduce strategy an...
sulfinamides, sulfonamides, and sulfonimidamides are in-demand motifs in medicinal chemistry, yet methods for the synthesis of alkyl variants that start from simple, readily available feedstocks scarce. In addition, bespoke syntheses each class molecules usually needed. this report, we detail these three distinct sulfur functional groups, using structurally diverse carboxylic acids as starting materials. The method harnesses radical generation acridine photocatalysts 400 nm light with...
The dedicated small-molecule single-crystal X-ray diffraction beamline (I19) at Diamond Light Source has been operational and supporting users for over three years. I19 is a high-flux tunable-wavelength its key details are described in this article. Much of the work performed on involves structure determination from small weakly diffracting crystals. Other experiments that have supported to date include structural studies high pressure, metastable species, variable-temperature...
Abstract Sulfonyl chlorides are inexpensive reactants extensively explored for functionalization, but never considered radical hydrosulfonylation of alkenes. Herein, we report that tris(trimethylsilyl)silane is an ideal hydrogen atom donor enabling highly effective photoredox‐catalyzed electron‐deficient alkenes with sulfonyl chlorides. To increase the generality this transformation, polarity‐reversal catalysis (PRC) was successfully implemented bearing alkyl substituents. This late‐stage...
Abstract The root microbiota is critical for agricultural yield, with growth-promoting bacteria able to solubilise phosphate, produce plant growth hormones, antagonise pathogens and fix N 2 . Plants control the microorganisms in their immediate environment this at least part through direct selection, immune system, interactions other microorganisms. Considering importance of crop yields it attractive artificially regulate optimise productivity. Towards aim we express a synthetic pathway...
Potassium fluoride (KF) is an ideal reagent for fluorination because it safe, easy to handle and low-cost. However, poor solubility in organic solvents coupled with limited strategies control its reactivity has discouraged use asymmetric C–F bond formation. Here, we demonstrate that hydrogen bonding phase-transfer catalysis KF provides access valuable β-fluoroamines high yields enantioselectivities. This methodology employs a chiral N-ethyl bis-urea catalyst brings solid into solution as...
A hydrogen borrowing reaction employing secondary alcohols and Ph* (Me5C6) ketones to give β-branched carbonyl products is described (21 examples). This new C-C bond forming process requires low loadings of [Cp*IrCl2]2, relatively temperatures, up 2.0 equiv the alcohol. Substrate-induced diastereoselectivity was observed, this represents first example a diastereoselective enolate alkylation. By utilizing group, could be straightforwardly cleaved corresponding esters or amides using...
Cyclo[18]carbon (C18, a molecular carbon allotrope) can be synthesized by dehalogenation of bromocyclocarbon precursor, C18Br6, in 64% yield, atomic manipulation on sodium chloride bilayer Cu(111) at 5 K, and imaged high-resolution force microscopy. This method generating C18 gives higher yield than that reported previously from the cyclocarbon oxide C24O6. The experimental images were compared with simulated for four theoretical model geometries, including possible bond-angle alternation:...
Bicyclo[1.1.0]butanes (BCBs), strained carbocycles comprising two fused cyclopropane rings, have become well-established building blocks in organic synthesis, medicinal chemistry, and chemical biology due to their diverse reactivity profile with radicals, nucleophiles, cations, carbenes. The constraints of the bicyclic ring system confer high p-character on interbridgehead C–C bond, leading this broad reaction profile; however, use BCBs pericyclic processes has date been largely overlooked...
Prediction of the outcome ring opening small organic rings under cationic conditions can be challenging due to intermediacy nonclassical carbocations. For example, solvolysis cyclobutyl or cyclopropylmethyl derivatives generates up four products on nucleophilic capture elimination via cyclopropylcarbinyl and bicyclobutonium ions. Here, we show that such reaction outcomes controlled by subtle changes structure carbocation. Using bicyclo[1.1.0]butanes as cation precursors, regio-...
A tetradentate halogen bond donor foldamer receptor framework is shown to exhibit enhanced anion recognition and chiral discrimination properties.
Ammonium salts are used as phase-transfer catalysts for fluorination with alkali metal fluorides. We now demonstrate that these organic salts, specifically azetidinium triflates, suitable substrates enantioselective ring opening CsF and a chiral bis-urea catalyst. This process, which highlights the ability of hydrogen bonding to couple two ionic reactants, affords enantioenriched γ-fluoroamines in high yields. Mechanistic studies underline role catalyst phase-transfer, computed transition...
Bicyclo[1.1.0]butanes (BCBs) are valuable precursors to four-membered rings and bicyclo[1.1.1]pentanes, useful bioconjugation agents. We describe a versatile approach access 1,3-disubstituted BCBs, which otherwise challenging prepare.
Molecules capable of mediating charge transport over several nanometers with minimal decay in conductance have fundamental and technological implications. Polymethine cyanine dyes are fascinating molecular wires because up to a critical length, they no bond-length alternation (BLA) their electronic structure resembles one-dimensional free-electron gas. Beyond this threshold, undergo symmetry-breaking Peierls transition, which increases the HOMO-LUMO gap. We investigated cationic cyanines...
Abstract Oligonucleotides that target mRNA have great promise as therapeutic agents for life-threatening conditions but suffer from poor bioavailability, hence high cost. As currently untreatable diseases come within the reach of oligonucleotide therapies, new analogues are urgently needed to address this. With this in mind we describe reduced-charge oligonucleotides containing artificial LNA-amide linkages with improved gymnotic cell uptake, RNA affinity, stability and potency. To construct...
The synthesis of red-shifted azobenzenes functionalised with heavy chalcogen and halogen substituents is reported, enabling photo-switching red near IR light Z → E thermal isomerization rates spanning seven orders magnitude.
Herein, we describe the convergent enantioselective total synthesis of himalensine A in 18 steps, enabled by a highly enantio- and diastereoselective construction morphan core via palladium/hydroxy proline co-catalyzed desymmetrization vinyl-bromide-tethered cyclohexanones. The reaction pathway was illuminated density functional theory calculations, which support an intramolecular Heck situ-generated enamine intermediate, where exquisite enantioselectivity arises from carboxylate...
Achieving single-step syntheses of a set related compounds divergently and selectively from common starting material affords substantial efficiency gains when compared with preparing those same by multiple individual syntheses. In order for this approach to be realized, complementary reagent systems must available; here, panel engineered P450BM3 enzymes is shown fulfill remit in the selective C–H hydroxylation cyclobutylamine derivatives at chemically unactivated sites. The oxidations can...
Ordering of the tetrahedral site vacancies in two crystals refined compositions K0.93(1)Fe1.52(1)Se2 and K0.862(3)Fe1.563(4)Se2 produces a fivefold expansion parent ThCr2Si2 unit cell ab plane which can accommodate 20% on single within square FeSe layer. The iron charge state is maintained close to +2 by coupling level alkali metal vacancies, producing potential doping mechanism operate at both average local structure levels.
Abstract Cumulenes are sometimes described as “metallic” because an infinitely long cumulene would have the band structure of a metal. Herein, we report single‐molecule conductance series cumulenes and analogues, where number consecutive C=C bonds in core is n =1, 2, 3, 5. The [ ]cumulenes with =3 5 almost same conductance, they both more conductive than alkene ( =1). This remarkable molecular normally falls exponentially length. allene =2) much lower, its twisted geometry. Computational...