Browse
Submit Data
Databases
API
Help

Dataset Information

19 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Exploring Possible Surrogates for Kobayashi's Aryne Precursors.

ABSTRACT: A class of aryne precursors, that is, 2-(trimethylsilyl)aryl 4-chlorobenzenesulfonates, has been developed through well-established synthetic routes, which allow the formation of arynes under relatively mild conditions. All the aryne precursors were obtained from phenols and 4-chlorobenzenesulfonyl chloride, an inexpensive and easy-to-handle reagent with relatively low toxicity, and subjected to nucleophilic addition reactions, providing addition products in yields of 24 to 92%, and to cycloaddition reactions, affording cycloadducts in yields up to 80%. This work provides interesting insights into the mechanisms of aryne generation. In addition, 2-(trimethylsilyl)phenyl 4-chlorobenzenesulfonate was successfully employed in the total synthesis of (±)-aporphine.

SUBMITTER: Muraca ACA

PROVIDER: S-EPMC7017410 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Exploring Possible Surrogates for Kobayashi's Aryne Precursors.

Muraca Ana Carolina A ACA Raminelli Cristiano C

ACS omega 20200131 5

A class of aryne precursors, that is, 2-(trimethylsilyl)aryl 4-chlorobenzenesulfonates, has been developed through well-established synthetic routes, which allow the formation of arynes under relatively mild conditions. All the aryne precursors were obtained from phenols and 4-chlorobenzenesulfonyl chloride, an inexpensive and easy-to-handle reagent with relatively low toxicity, and subjected to nucleophilic addition reactions, providing addition products in yields of 24 to 92%, and to cycloaddi ...[more]

PMID: 32064404

Similar Datasets

Silylaryl Halides Can Replace Triflates as Aryne Precursors.

Project description:Silylaryl bromides and iodides can be prepared in one step from commercially available starting materials. Arynes can be generated from these compounds under conditions nearly identical to those employed for silylaryl triflates. Three distinct transformations, ortho-arylation of N-tritylanilines, intermolecular addition of arynes to amides, and reaction of ureas with arynes, were shown to be successful for the new aryne precursors. The main advantage of silylaryl halides relative to silyl aryl triflates is their one-step preparation from commercially available starting materials.

| S-EPMC5020908 | biostudies-literature

Aryne cycloaddition reactions of benzodioxasilines as aryne precursors generated by catalytic reductive <i>ortho</i>-C-H silylation of phenols with traceless acetal directing groups.

Project description:Diversely substituted arylsilyl triflates, as aryne precursors for aryne cycloaddition reactions, were accessed from benzodioxasilines. Catalytic reductive C-H ortho-silylation of phenols with traceless acetal directing groups was exploited to prepare benzodioxasilines. Sequential addition of MeLi and then trifluoromethanesulfonic anhydride to benzodioxasilines provided arylsilyl triflates in a single pot. Notably, this approach was successfully utilized to prepare sterically hindered 1,2,3-trisubstituted arylsilyl triflates, which ultimately underwent fluoride-mediated aryne cycloaddition.

| S-EPMC5501486 | biostudies-literature

Boryl (Hetero)aryne Precursors as Versatile Arylation Reagents: Synthesis through C-H Activation and Orthogonal Reactivity.

Project description:(Pinacolato)boryl ortho-silyl(hetero)aryl triflates are presented as a new class of building blocks for arylation. They demonstrate unique versatility by delivering boronate or (hetero)aryne reactivity chemoselectively in a broad range of transformations. This approach enables the unprecedented postfunctionalization of fluoride-activated (hetero)aryne precursors, for example, as substrates in transition-metal catalysis, and offers valuable new possibilities for aryl boronate postfunctionalization without the use of specialized protecting groups.

| S-EPMC4600243 | biostudies-literature

Group 4 Diarylmetallocenes as Bespoke Aryne Precursors for Titanium-Catalyzed [2 + 2 + 2] Cycloaddition of Arynes and Alkynes.

Project description:Despite the ubiquity of reports describing titanium (Ti)-catalyzed [2 + 2 + 2] cyclotrimerization of alkynes, the incorporation of arynes into this potent manifold has never been reported. The in situ generation of arynes often requires fluoride, which instead will react with the highly fluorophilic Ti center, suppressing productive catalysis. Herein, we describe the use of group 4 diarylmetallocenes, CpR2MAr2 (CpR = C5H5, C5Me5; M = Ti, Zr), as aryne precursors for the Ti-catalyzed synthesis of substituted naphthalenes via coupling with 2 equiv of an alkyne. Fair-to-good yields of the desired naphthalene products could be obtained with 1% catalyst loadings, which is roughly an order of magnitude lower than similar reactions catalyzed by palladium or nickel. Additionally, naphthalenes find broad applications in the electronics, photovoltaics, and pharmaceutical industries, urging the discovery of more economic syntheses. These results indicate that aryne transfer from a CpR2M(?2-aryne) complex to another metal is a viable route for the introduction of aryne fragments into organometallic catalytic processes.

| S-EPMC7201866 | biostudies-literature

K562 erythroleukemia line as a possible reticulocyte source to culture Plasmodium vivax and its surrogates.

Project description:Establishing an in vitro "red blood cell matrix" that would allow uninterrupted access to a stable, homogeneous reticulocyte population would facilitate the establishment of continuous, long-term in vitro Plasmodium vivax blood stage cultures. In this study, we have explored the suitability of the erythroleukemia K562 cell line as a continuous source of such reticulocytes and have investigated regulatory factors behind the terminal differentiation (and enucleation, in particular) of this cell line that can be used to drive the reticulocyte production process. The Duffy blood group antigen receptor (Fy), essential for P. vivax invasion, was stably introduced into K562 cells by lentiviral gene transfer. miRNA-26a-5p and miRNA-30a-5p were downregulated to promote erythroid differentiation and enucleation, resulting in a tenfold increase in the production of reticulocytes after stimulation with an induction cocktail compared with controls. Our results suggest an interplay in the mechanisms of action of miRNA-26a-5p and miRNA-30a-5p, which makes it necessary to downregulate both miRNAs to achieve a stable enucleation rate and Fy receptor expression. In the context of establishing P. vivax-permissive, stable, and reproducible reticulocytes, a higher enucleation rate may be desirable, which may be achieved by the targeting of further regulatory mechanisms in Fy-K562 cells; promoting the shift in hemoglobin production from fetal to adult may also be necessary. Despite the fact that K562 erythroleukemia cell lines are of neoplastic origin, this cell line offers a versatile model system to research the regulatory mechanisms underlying erythropoiesis.

| S-EPMC7097847 | biostudies-literature

The Aryne Phosphate Reaction.

Project description:Condensed phosphates are a critically important class of molecules in biochemistry. Non-natural analogues are important for various applications, such as single-molecule real-time DNA sequencing. Often, such analogues contain more than three phosphate units in their oligophosphate chain. Consequently, investigations into phosphate reactivity enabling new ways of phosphate functionalization and oligophosphorylation are essential. Here, we scrutinize the potential of phosphates to act as arynophiles, paving the way for follow-up oligophosphorylation reactions. The aryne phosphate reaction is a powerful tool to-depending on the perspective-(oligo)phosphorylate arenes or arylate (oligo-cyclo)phosphates. Based on Kobayashi-type o-silylaryltriflates, the aryne phosphate reaction enables rapid entry into a broad spectrum of arylated products, like monophosphates, diphosphates, phosphodiesters and polyphosphates. The synthetic potential of these new transformations is demonstrated by efficient syntheses of nucleotide analogues and an unprecedented one-flask octaphosphorylation.

| S-EPMC9299019 | biostudies-literature

The role of aryne distortions, steric effects, and charges in regioselectivities of aryne reactions.

Project description:The distortion/interaction model has been used to explain and predict reactivity in a variety of reactions where more common explanations, such as steric and electronic factors, do not suffice. This model has also provided new fundamental insight into regioselectivity trends in reactions of unsymmetrical arynes, which in turn has fueled advances in aryne methodology and natural product synthesis. This article describes a systematic experimental and computational study of one particularly important class of arynes, 3-halobenzynes. 3-Halobenzynes are useful synthetic building blocks whose regioselectivities have been explained by several different models over the past few decades. Our efforts show that aryne distortion, rather than steric factors or charge distribution, are responsible for the regioselectivities observed in 3-haloaryne trapping experiments. We also demonstrate the synthetic utility of 3-halobenzynes for the efficient synthesis of functionalized heterocycles, using a tandem aryne-trapping/cross-coupling sequence involving 3-chlorobenzyne.

| S-EPMC4221504 | biostudies-literature

Coexistence of genetic conditions: exploring a possible relationship.

Project description:We report on a 3-year-old boy who has congenital adrenal hyperplasia and a suspected Van Maldergem syndrome, another genetic condition, with the classic phenotype seen in our patient. The latter diagnosis was supported by a genetic test that showed a novel and likely pathogenic variant in a previously described gene of the syndrome. Paediatricians do encounter such a challenge of coexisting genetic conditions albeit infrequently, and advanced genetic analysis, example whole exome sequencing, increasingly report variants of unknown significance with a variable degree of potential pathogenicity. The treating physician needs to follow a systematic approach and entertain thorough literature search and brainstorming in order to prove or disprove any possible relationship between coexisting genetic conditions. The first step should be confirming the existence of the two conditions in the first place. In addition, when family segregation is unable to confidently make a sensible conclusion in such cases, a clinician should proceed to advanced functional studies to confirm pathogenicity. Then, one can explore further any hidden relationship between coexisting and possibly clinically-related genetic conditions.

| S-EPMC6589797 | biostudies-literature

"It hurts to know... and it helps": exploring how surrogates in the ICU cope with prognostic information.

Project description:Surrogates of critically ill patients in the intensive care unit (ICU) want honest prognostic information, but they also want to hear good news. There has been little examination of how surrogates navigate these dual needs or how clinicians should respond.The aim of this study was explore how surrogates in the ICU experience and cope with prognostic information and describe their recommendations for clinicians.We conducted a qualitative interview study with 30 surrogates facing life-sustaining treatment decisions in five ICUs in Pittsburgh, Pennsylvania. In-depth, semi-structured interviews with surrogates in the ICU focused on general experiences, emotional needs, informational needs, and recommendations for clinicians. We inductively analyzed transcripts for key themes using constant comparative methods.Surrogates experience a tension between wanting to know what to expect and needing to remain hopeful. This tension underlies their experience receiving prognostic information and may lead to behaviors that allow continued hope in the face of bad news, including: 1) focusing on small details rather than the big picture, 2) relying on gut instincts or personal beliefs about the patient, 3) seeking more positive prognostic information from other sources, and, for a minority, 4) avoiding or disbelieving prognostic information. Surrogates emphasize the importance of frequent communication and call on physicians to gently help them prepare for the worst and hope for the best.Surrogates in the ICU experience conflicting emotional and informational needs. They describe behaviors that give the appearance of avoiding bad news while simultaneously asking physicians to help them cope with prognostic information.

| S-EPMC3583249 | biostudies-other

Intracellular distribution of serum albumin and its possible precursors in rat liver.

Project description:1. The fractionation of intracellular albumin labelled with radioactive l-leucine was studied in rat liver by means of isoelectric focusing. 2. Isoelectric fractionation was compared with ion-exchange chromatography for purification of radioactive intracellular albumin obtained by antibody precipitation. Similar results were obtained with both methods of separation. Purified albumin contains only a minor amount of the radioactivity. The remainder is associated with albumin-like protein(s). 3. The albumin-like protein has the properties of a precursor of plasma albumin. 4. The distribution and turnover of radioactive albumin in rough and smooth microsomal fractions and in a Golgi-rich fraction were studied. 5. It is concluded that newly synthesized albumin, as such, appears only momentarily if at all in any intracellular structure before its appearance in the plasma. 6. It is also concluded that the rate-limiting step in the secretion of plasma albumin is the conversion of precursor(s) into albumin. We can find no evidence to suggest that there is any significant transport of albumin, as such, during the course of secretion.

| S-EPMC1178796 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

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