A5025870305- Synthetic Organic Chemistry Methods
- Chemical Synthesis and Analysis
- Chemical Synthesis and Reactions
- Asymmetric Hydrogenation and Catalysis
- Oxidative Organic Chemistry Reactions
- Microbial Natural Products and Biosynthesis
- Asymmetric Synthesis and Catalysis
- Radical Photochemical Reactions
- Fluorine in Organic Chemistry
- Marine Sponges and Natural Products
- Synthesis and Catalytic Reactions
- Plant-derived Lignans Synthesis and Bioactivity
- Carbohydrate Chemistry and Synthesis
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Advanced Synthetic Organic Chemistry
- Catalytic C–H Functionalization Methods
- Chromatography in Natural Products
- Synthesis and Biological Evaluation
- Marine Toxins and Detection Methods
- Inorganic and Organometallic Chemistry
- Organoboron and organosilicon chemistry
- Magnolia and Illicium research
- Traditional and Medicinal Uses of Annonaceae
- Cyclopropane Reaction Mechanisms
University of Nottingham
2014-2024
GlaxoSmithKline (United Kingdom)
2018-2024
Normandie Université
2023
Indian Institute of Chemical Technology
2023
University of Bath
2023
Academy of Scientific and Innovative Research
2023
Humboldt-Universität zu Berlin
2023
Central University of Punjab
2023
Central Drug Research Institute
2023
Indian Institute of Engineering Science and Technology, Shibpur
2023
Displacing OH groups catalytically The Mitsunobu reaction is widely used to invert the configuration of alcohols. However, its major drawback need activate alcohol with a full equivalent phosphine, thereby generating phosphine oxide co-product. Beddoe et al. report compound that achieves same result (see Perspective by Longwitz and Werner). key phenol substituent can reversibly bond through oxygen phosphorus, forming ring opens. phosphorus thus remains in +5 oxidation state throughout...
Catalytic phosphorus(V)-mediated chlorination and bromination reactions of alcohols have been developed. The new constitute a catalytic version the classical Appel halogenation reaction. In these oxalyl chloride is used as consumable stoichiometric reagent to generate halophosphonium salts responsible for from phosphine oxides. Thus, oxides transformed waste products into catalysts concept phosphorus-based activation nucleophilic substitution has validated. present study focused on full...
A phosphine oxide-catalysed chlorination reaction of primary and secondary alcohols has been developed. This process represents the first triphenylphosphine alcohol under Appel conditions.
Bimolecular nucleophilic substitution reactions of alcohols are fundamentally important transformations in organic chemistry yet, to date, they relatively underdeveloped with respect catalysis. This Article describes the emerging area catalytic SN2 specific emphasis on design and development phosphorus(V) cyclopropenone-based alcohols.
γ-Secretase inhibitors are one promising approach to the development of a therapeutic for Alzheimer9s disease (AD). reduce brain β-amyloid peptide (Aβ), which is believed be major contributor in etiology AD. Transgenic mice overexpressing human precursor protein (APP) valuable models examine dynamics Aβ changes with γ-secretase plaque-free and plaque-bearing animals. BMS-299897 2-[(1<i>R</i>)-1-[[(4-chlorophenyl)sulfony](2,5-difluorophenyl)amino]ethyl]-5-fluorobenzenepropanoic acid,...
The molecular design, chemical synthesis, and biological evaluation of two distinct series platensimycin analogues with varying degrees complexity are described. first compounds probes the importance benzoic acid subunit molecule, while second explores tetracyclic cage domain. data obtained reveal that, substituted domain is a highly conserved structural motif within active strict functional group requirements, molecule can tolerate considerable modifications without losing action. These...
Adamantly pursuing the bugs: The syntheses of two enantiomers adamantaplatensimycin ((−)-1 and (+)-1), a novel analogue newly discovered antibiotic platensimycin, have been achieved. Potent antibacterial action against methicillin-resistant Staphylococcus aureus vancomycin-resistant Enterococcus faecium has revealed for (−) enantiomer.
A stereospecific triphenylphosphine oxide-catalyzed 1,2-dichlorination reaction of epoxides has been developed. The is effective for a range terminal and internal epoxides. In contrast to the classical Appel-type dichlorination epoxides, oxalyl chloride used as stoichiometric reagent generate chlorophosphonium salt responsible from catalytic oxide.
Retinoic acid receptor (RAR) signaling is required for morphogenesis of the ventral optic cup and closure choroid fissure, but mechanisms by which this pathway regulates eye development remain controversial poorly understood. Although previous studies have implicated neural crest-derived periocular mesenchyme (POM) as critical target RA action in eye, we show here that RAR fissure zebrafish acting on both POM. We describe RAR-dependent regulation eight genes neuroepithelial cells retina...
Abstract Amines are a fundamentally important class of biologically active compounds and the ability to manipulate their physicochemical properties through introduction fluorine is paramount importance in medicinal chemistry. Current synthesis methods for construction fluorinated amines rely on air moisture sensitive reagents that require special handling or harsh reductants limit functionality. Here we report practical, catalyst-free, reductive trifluoroethylation reactions free exhibiting...
As the largest secondary metabolite to be discovered as of yet, polyether marine neurotoxin maitotoxin constitutes a major structural and synthetic challenge. After its originally proposed structure (1) had been questioned on basis biosynthetic considerations, we provided computational experimental support for 1. In an effort provide stronger evidence molecular architecture maitotoxin, GHIJKLMNO ring system 3 was synthesized. The 13C NMR chemical shifts matched closely those corresponding...
We report a catalytic reductive alkylation reaction of primary or secondary amines with carboxylic acids. The two-phase process involves silane mediated direct amidation followed by reduction.
We report reductive alkylation reactions of amines using carboxylic acids as nominal electrophiles.
Accepting the proposal: The originally proposed structure of maitotoxin has recently come under scrutiny based on biosynthetic and computational considerations. A newly synthesized ring framework corresponding to GHIJK domain (see structure) molecule provided, through 13C NMR spectroscopic comparisons, strong experimental support for structure. Maitotoxin is a notorious marine neurotoxin that possesses unsurpassed molecular size toxicity compared any other known secondary metabolite.1–4 In...
We report a synthesis method for the construction of quaternary aryl phoshonium salts at ambient temperature. The regiospecific reaction involves coupling phosphines with radicals derived from diaryliodonium under photoredox conditions.
Herein, we report a green, chromatography-free Appel chlorination and bromination in both catalytic stoichiometric form. Improved sustainability was achieved via the effective replacement of chlorinated solvents with dimethyl carbonate use triphenylphosphine oxide (PPh3O) as recyclable organocatalyst. The substrate scope this halogenated solvent-free reaction shown to be analogous contemporary methodology, removal recovery PPh3O from desired products were effectively demonstrated....
We describe in full the first synthesis of potent insect antifeedant azadirachtin through a highly convergent approach. An O-alkylation reaction is used to unite decalin ketone and propargylic mesylate fragments, after which Claisen rearrangement constructs central C8-C14 bond stereoselective fashion. The allene results from this sequence then enables second critical carbon-carbon forming event whereby [3.2.1] bicyclic system, present natural product, generated via 5-exo-radical cyclisation...
Abstract Silyl esters have been exploited as metastable reaction intermediates, both purposefully and unintentionally, since at least the 1960s. Their reactivity is broadly related to substituents on silicon, in this way their properties can be readily modulated. unique profiles that used generate downstream products of a range functionalities, because many excellent methods for synthesis variety value-added chemicals developed. Furthermore, frequent use hydrosilanes terminal reductants...
Sulfinate-mediated radical C–H functionalisation reactions are widely used for the modification and diversification of scaffolds in drug discovery. However, prediction regiochemistry can be challenging. There may multiple sites reaction, each with its own unique steric electronic environment. Here we present Rega, an automated transition state searching program regioselectivity from inexpensive HF/6-31G* activation energies. In a set 23 compounds is correctly identified 22 cases (reactivity...
The development of the first redox-free protocol for Mitsunobu reaction is described. This has been achieved by exploiting triphenylphosphine oxide--the unwanted by-product in conventional reaction--as precursor to active P(V) coupling reagent. Multinuclear NMR studies are consistent with hydroxyl activation via an alkoxyphosphonium salt.
We report a concise and modular approach to α,α-diaryl α-amino esters from readily available α-keto esters. This mild, one-pot protocol proceeds via ketone umpolung, with in situ formation of Kukhtin-Ramirez intermediate preceding sequential electrophilic arylation by Bi(V) SN2 displacement an amine. The methodology is compatible wide range anilines primary amines - including derivatives drugs proteinogenic amino acids arylating agents, ester substrates.
We describe a catalytic system for the conversion of carboxylic acids into alcohols using substoichiometric zinc acetate and N-methyl morpholine, in combination with phenylsilane as nominal terminal reductant. Reaction monitoring by 19F NMR spectroscopy demonstrates that reaction proceeds mutual activation acid silane through situ generation silyl ester intermediates.