Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

On 1,3-phosphaazaallenes and their diverse reactivity.

ABSTRACT: 1,3-Phosphaazaallenes are heteroallenes of the type RP[double bond, length as m-dash]C[double bond, length as m-dash]NR' and little is known about their reactivity. In here we describe the straightforward synthesis of ArPCNR (Ar = Mes*, 2,4,6-tBu-C₆H₂; ^MesTer, 2.6-(2,4,6-Me₃C₆H₂)-C₆H₃; ^DipTer, 2.6-(2,6-iPr₂C₆H₂)-C₆H₃; R = tBu; Xyl, 2,6-Me₂C₆H₃) starting from phospha-Wittig reagents ArPPMe₃ and isonitriles CNR. It is further shown that ArPCNtBu are thermally labile with respect to the loss of iso-butene and it is shown that the cyanophosphines ArP(H)CN are synthetically feasible and form the corresponding phosphanitrilium borates with B(C₆F₅)₃, whereas deprotonation of ^DipTerP(H)CN was shown to give an isolable cyanidophosphide. Lastly, the reactivity of ArPCNR towards Pier's borane was investigated, showing hydroboration of the C[double bond, length as m-dash]N bond in Mes*PCNtBu to give a hetero-butadiene, while with ^DipTerPCNXyl the formation of the Lewis acid-base adduct with a B-P linkage was observed.

SUBMITTER: Fischer M

PROVIDER: S-EPMC8336469 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

On 1,3-phosphaazaallenes and their diverse reactivity.

Fischer Malte M Hering-Junghans Christian C

Chemical science 20210630 30

1,3-Phosphaazaallenes are heteroallenes of the type RP[double bond, length as m-dash]C[double bond, length as m-dash]NR' and little is known about their reactivity. In here we describe the straightforward synthesis of ArPCNR (Ar = Mes*, 2,4,6-tBu-C6H2; MesTer, 2.6-(2,4,6-Me3C6H2)-C6H3; DipTer, 2.6-(2,6-iPr2C6H2)-C6H3; R = t ...[more]

PMID: 34377415

Similar Datasets

Site of reactivity models predict molecular reactivity of diverse chemicals with glutathione.

Project description:Drug toxicity is often caused by electrophilic reactive metabolites that covalently bind to proteins. Consequently, the quantitative strength of a molecule's reactivity with glutathione (GSH) is a frequently used indicator of its toxicity. Through cysteine, GSH (and proteins) scavenges reactive molecules to form conjugates in the body. GSH conjugates to specific atoms in reactive molecules: their sites of reactivity. The value of knowing a molecule's sites of reactivity is unexplored in the literature. This study tests the value of site of reactivity data that identifies the atoms within 1213 reactive molecules that conjugate to GSH and builds models to predict molecular reactivity with glutathione. An algorithm originally written to model sites of cytochrome P450 metabolism (called XenoSite) finds clear patterns in molecular structure that identify sites of reactivity within reactive molecules with 90.8% accuracy and separate reactive and unreactive molecules with 80.6% accuracy. Furthermore, the model output strongly correlates with quantitative GSH reactivity data in chemically diverse, external data sets. Site of reactivity data is nearly unstudied in the literature prior to our efforts, yet it contains a strong signal for reactivity that can be utilized to more accurately predict molecule reactivity and, eventually, toxicity.

| S-EPMC5871349 | biostudies-literature

Structure-reactivity relationships of zwitterionic 1,3-diaza-Claisen rearrangements.

Project description:Bridged bicyclic tertiary allylic amines aza-norbornene 1 and isoquinuclidene 2 add to isocyanates, isothiocyanates, and in situ-generated carbodiimides to form zwitterionic intermediates that undergo 1,3-diaza-Claisen rearrangements to afford highly substituted ureas, thioureas, and guanidines, respectively. Aza-norbornene 1 is significantly more reactive toward 1,3-diaza-Claisen rearrangements than isoquinuclidene 2. This reactivity difference is most likely due to the inherent ring strain in the aza-bicyclo[2.2.1]heptene ring system of aza-norbornene 1. The most apparent reactivity trend of the heterocumulenes is that the most electron-deficient heterocumulenes are more reactive toward 1,3-diaza-Claisen rearrangements. The introduction of a new stereocenter α- to the nucleophilic nitrogen in aza-norbornene 1 and isoquinuclidine 2 decreases the reactivity toward 1,3-diaza-Claisen rearrangements, while the exodiastereomers 3b and 4b are less reactive than the corresponding endodiastereomers 3a and 4a. Isocyanates that bear an electron-withdrawing group react with allylic amines 1-3b to afford mixtures of ureas and isoureas; however, with excess isocyanate and heat, thermodynamic equilibration is possible affording ureas. Inspired by this observation, a one-pot reaction of isocyanates with amines 1, 2, and 3b followed by BF3·OEt2-catalyzed isomerization of the urea/isourea mixture was developed that affords the corresponding ureas in excellent yields.

| S-EPMC4356197 | biostudies-literature

Diverse Redoxome Reactivity Profiles of Carbon Nucleophiles.

Project description:Targeted covalent inhibitors have emerged as a powerful approach in the drug discovery pipeline. Key to this process is the identification of signaling pathways (or receptors) specific to (or overexpressed in) disease cells. In this context, fragment-based ligand discovery (FBLD) has significantly expanded our view of the ligandable proteome and affords tool compounds for biological inquiry. To date, such covalent ligand discovery has almost exclusively employed cysteine-reactive small-molecule fragments. However, functional cysteine residues in proteins are often redox-sensitive and can undergo oxidation in cells. Such reactions are particularly relevant in diseases, like cancer, which are linked to excessive production of reactive oxygen species. Once oxidized, the sulfur atom of cysteine is much less reactive toward electrophilic groups used in the traditional FBLD paradigm. To address this limitation, we recently developed a novel library of diverse carbon-based nucleophile fragments that react selectively with cysteine sulfenic acid formed in proteins via oxidation or hydrolysis reactions. Here, we report analysis of sulfenic acid-reactive C-nucleophile fragments screened against a colon cancer cell proteome. Covalent ligands were identified for >1280 S-sulfenylated cysteines present in "druggable" proteins and orphan targets, revealing disparate reactivity profiles and target preferences. Among the unique ligand-protein interactions identified was that of a pyrrolidinedione nucleophile that reacted preferentially with protein tyrosine phosphatases. Fragment-based covalent ligand discovery with C-nucleophiles affords an expansive snapshot of the ligandable "redoxome" with significant implications for covalent inhibitor pharmacology and also affords new chemical tools to investigate redox-regulation of protein function.

| S-EPMC5898444 | biostudies-literature

Diverse Autoantibody Reactivity in Cartilage-Hair Hypoplasia.

Project description: Not available

| S-EPMC6104642 | biostudies-literature

Factors Controlling the Diels-Alder Reactivity of Hetero-1,3-Butadienes.

Project description:We have quantum chemically explored the Diels-Alder reactivities of a systematic series of hetero-1,3-butadienes with ethylene by using density functional theory at the BP86/TZ2P level. Activation strain analyses provided physical insight into the factors controlling the relative cycloaddition reactivity of aza- and oxa-1,3-butadienes. We find that dienes with a terminal heteroatom, such as 2-propen-1-imine (NCCC) or acrolein (OCCC), are less reactive than the archetypal 1,3-butadiene (CCCC), primarily owing to weaker orbital interactions between the more electronegative heteroatoms with ethylene. Thus, the addition of a second heteroatom at the other terminal position (NCCN and OCCO) further reduces the reactivity. However, the introduction of a nitrogen atom in the backbone (CNCC) leads to enhanced reactivity, owing to less Pauli repulsion resulting from polarization of the diene HOMO in CNCC towards the nitrogen atom and away from the terminal carbon atom. The Diels-Alder reactions of ethenyl-diazene (NNCC) and 1,3-diaza-butadiene (NCNC), which contain heteroatoms at both the terminal and backbone positions, are much more reactive due to less activation strain compared to CCCC.

| S-EPMC6276106 | biostudies-literature

Diverse modes of reactivity of 6-(chloromethyl)-6-methylfulvene.

Project description:The title compound exhibits a number of reactivities toward nucleophiles/bases owing to the presence of several electrophilic and potentially nucleophilic sites in the molecule. We explored the reactions of 6-(chloromethyl)-6-methylfulvene with oxygen- and nitrogen nucleophiles and bases as well as a carbon-based nucleophile (an enamine) and realized all possible reactivity modes predicted on the basis of electrophilic and nucleophilic positions in this compound.

| S-EPMC5708559 | biostudies-literature

Different Reactivity of Raw Starch from Diverse Potato Genotypes.

Project description:Potato starch is one of the most important renewable sources for industrial manufacturing of organic compounds. Currently, it is produced from mixed potato varieties that often are harvested from different fields. Meanwhile, tuber starches of various potato breeds differ in their crystallinity, granule morphology, and other physical and chemical parameters. We studied the reactions of raw potato starches of different origins to chemical and biochemical reactions typically used for industrial starch modification. The results clearly demonstrate that there is a significant difference in the reactivity of the starches of different potato genotypes. While the main products of the transformations are the same, their preparative yields differ significantly. Thus, tuber starch of certain potato varieties may be more suitable for specific industrial purposes. Starch reactivity may potentially be a phenotypical trait for potato breeding to obtain potato starches for various industrial applications.

| S-EPMC7795658 | biostudies-literature

Reactivity and kinetics of 1,3-butadiene under ultraviolet irradiation at 254 nm.

Project description:The reaction process of gaseous 1,3-butadiene following ultraviolet irradiation at the temperature range from 298 to 323 K under nitrogen atmosphere was monitored by UV-vis spectrophotometry. A gaseous mini-reactor was used as a reaction vessel and could be directly monitored in a UV-vis spectrophotometer. We investigated the reactivity and kinetics of 1,3-butadiene under non-UV and UV irradiation to evaluate its photochemical stability. A second-order kinetic model with 50.48 kJ·mol-1 activation energy fitted the reaction data for non-UV irradiation, whereas a first-order kinetic model was appropriate in the case of UV irradiation with activation energies of 19.92-43.65 kJ mol-1. This indicates that ultraviolet light could accelerate the photolysis reaction rate of 1,3-butadiene. In addition, the reaction products were determined using gas chromatography-mass spectrometry (GC-MS), and the reaction pathways were identified. The photolysis of 1,3-butadiene gave rise to various volatile products by cleavage and rearrangement of single C-C bonds. The differences between dimerization and dissociation of 1,3-butadiene under ultraviolet irradiation were elucidated by combining experimental and theoretical methods. The present findings provide fundamental insight into the photochemistry of 1,3-butadiene compounds.

| S-EPMC8857861 | biostudies-literature

Diverse reactivity of an iron-aluminium complex with substituted pyridines.

Project description:The reaction of an Fe-Al complex with an array of substituted pyridines is reported. Depending on the substitution pattern of the substrate site-selective sp2 or sp3 C-H bond activation is observed. A series of reaction products are observed based on (i) C-Al bond formation, (ii) C-C bond formation by nucleophilic addition or (iii) deprotonation of the β-diketiminate ligand. A divergent set of mechanisms involving a common intermediate is proposed.

| S-EPMC9514013 | biostudies-literature

An air- and moisture-stable ruthenium precatalyst for diverse reactivity.

Project description:Versatile, efficient and robust (pre)catalysts are pivotal in accelerating the discovery and optimization of chemical reactions, shaping diverse synthetic fields such as cross-coupling, C-H functionalization and polymer chemistry. Yet, their scarcity in certain domains has hindered the advancement and adoption of new applications. Here we present a highly reactive air- and moisture-stable ruthenium precatalyst [(tBuCN)5Ru(H2O)](BF4)2, featuring a key exchangeable water ligand. This versatile precatalyst drives an array of transformations, including late-stage C(sp2)-H arylation, primary/secondary alkylation, methylation, hydrogen/deuterium exchange, C(sp3)-H oxidation, alkene isomerization and oxidative cleavage, consistently outperforming conventionally used ruthenium (pre)catalysts. The generality and applicability of this precatalyst is exemplified through the potential for rapid screening and optimization of photocatalytic reactions with a suite of in situ generated ruthenium photocatalysts containing hitherto unknown complexes, and through the rapid discovery of reactivities previously unreported for ruthenium. The diverse applicability observed is suggestive of a generic platform for reaction simplification and accelerated synthetic discovery that will enable broader applicability and accessibility to state-of-the-art ruthenium catalysis.

| S-EPMC11230907 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data