Browse
Submit Data
Databases
API
Help

Dataset Information

33 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Competitive formation of homocircuit [3]rotaxanes in synthetically useful yields in the bipyridine-mediated active template CuAAC reaction.

ABSTRACT: We recently identified competitive formation of doubly interlocked [3]rotaxanes as the origin of the non-linear variation in yield of [2]rotaxane with macrocycle size in the bipyridine-mediated AT-CuAAC reaction. Selection of reaction conditions gave [2]rotaxanes in essentially quantitative yield in all cases and hard to access doubly threaded [3]rotaxanes in up to 50% yield in a single, four component coupling. Based on the effect of macrocycle structure on the reaction outcome we propose a detailed mechanism of [3]rotaxane formation.

SUBMITTER: Neal EA

PROVIDER: S-EPMC5645920 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Diastereoselective synthesis of [1]rotaxanes <i>via</i> an active metal template strategy.

Project description:Despite the impressive number of interlocked molecules described in the literature over the past 30 years, only a few stereoselective syntheses of mechanically chiral rotaxanes have been reported so far. In this study, we present the first diastereoselective synthesis of mechanically planar chiral [1]rotaxanes, that has been achieved using the active template Cu-mediated alkyne-azide cycloaddition reaction. This synthetic method has been applied to the preparation of a [1]rotaxane bearing a labile stopper that can then be substituted without disruption of the mechanical bond. This approach paves the way for the synthesis of a wide variety of mechanically planar chiral [1]rotaxanes, hence allowing the study of the properties and potential applications of this class of interlocked molecular architectures.

| S-EPMC8179266 | biostudies-literature

Selective access to constitutionally identical, orientationally isomeric calix[6]arene-based [3]rotaxanes by an active template approach.

Project description:Tris(phenylureido)calix[6]arene is endowed with unique properties that make it a valuable macrocyclic component for the synthesis of mechanically interlocked molecules. Its three-dimensional and intrinsically nonsymmetric structure is kinetically selective toward two processes: (i) in apolar media, the threading of bipyridinium based axle-like components takes place exclusively from the upper rim; (ii) SN2 alkylation reactions of a pyridylpyridinium precursor engulfed in the cavity occur selectively at pyridylpyridinium nitrogen atom located at the macrocycle upper rim (active template synthesis). Here we exploit such properties to prepare two series of [3]rotaxanes, each consisting of three sequence isomers that arise from the threading of two identical but nonsymmetric wheels on a symmetric thread differing only for the reciprocal orientation of the macrocycles. The features of the calix[6]arene and the active template synthetic approach, together with a careful selection of the precursors, enabled us to selectively synthesise the [3]rotaxane sequence isomers of each series with fast kinetics and high yields.

| S-EPMC8115267 | biostudies-literature

SYNTHETICALLY USEFUL INTERMEDIATES BY DIAZOSULFONE AND SULFONATE C-H INSERTION.

Project description:Intramolecular C-H insertion on diazosulfone and diazosulfonate substrates was used to prepare synthetically useful intermediates from easily available starting materials.

| S-EPMC4278664 | biostudies-literature

Ru(II)Porphyrinate-based molecular nanoreactor for carbene insertion reactions and quantitative formation of rotaxanes by active-metal-template syntheses.

Project description:Selectivity in N-H and S-H carbene insertion reactions promoted by Ru(II)porphyrinates currently requires slow addition of the diazo precursor and large excess of the primary amine and thiol substrates in the reaction medium. Such conditions are necessary to avoid the undesirable carbene coupling and/or multiple carbene insertions. Here, the authors demonstrate that the synergy between the steric shielding provided by a Ru(II)porphyrinate-based macrocycle with a relatively small central cavity and the kinetic stabilization of otherwise labile coordinative bonds, warranted by formation of the mechanical bond, enables single carbene insertions to occur with quantitative efficiency and perfect selectivity even in the presence of a large excess of the diazo precursor and stoichiometric amounts of the primary amine and thiol substrates. As the Ru(II)porphyrinate-based macrocycle bears a confining nanospace and alters the product distribution of the carbene insertion reactions when compared to that of its acyclic version, the former therefore functions as a nanoreactor.

| S-EPMC7733472 | biostudies-literature

Chemical Consequences of the Mechanical Bond: A Tandem Active Template-Rearrangement Reaction.

Project description:We report the unexpected discovery of a tandem active template CuAAC-rearrangement process, in which N2 is extruded on the way to the 1,2,3-triazole product to give instead acrylamide rotaxanes. Mechanistic investigations suggest this process is dictated by the mechanical bond, which stabilizes the CuI -triazolide intermediate of the CuAAC reaction and diverts it down the rearrangement pathway; when no mechanical bond is formed, the CuAAC product is isolated.

| S-EPMC6589916 | biostudies-literature

Efficient production of [n]rotaxanes by using template-directed clipping reactions.

Project description:In this article, we report on the efficient synthesis of well defined, homogeneous [n]rotaxanes (n up to 11) by a template-directed thermodynamic clipping approach. By employing dynamic covalent chemistry in the form of reversible imine bond formation, [n]rotaxanes with dialkylammonium ion (-CH(2)NH(2)(+)CH(2)-) recognition sites, encircled by [24]crown-8 rings, were prepared by a thermodynamically controlled, template-directed clipping procedure, that is, by mixing together a dumbbell compound containing a discrete number of CH(2)NH(2)(+)CH(2)- ion centers with appropriate amounts of a dialdehyde and a diamine to facilitate the [n]rotaxane formation. A 21-component self-assembly process is operative during the formation of the [11]rotaxane. The oligomeric dumbbells containing CH(2)NH(2)(+)CH(2)- ion recognition sites were prepared by a stepwise protocol. Several of the dynamic [n]rotaxanes were converted into their kinetically stable counterparts, first by reduction ("fixing") of imine bonds with the BH(3).THF complex, then by protonation of the complex by addition of acid.

| S-EPMC2077244 | biostudies-literature

High yielding synthesis of 2,2'-bipyridine macrocycles, versatile intermediates in the synthesis of rotaxanes.

Project description:We present an operationally simple approach to 2,2'-bipyridine macrocycles. Our method uses simple starting materials to produce these previously hard to access rotaxane precursors in remarkable yields (typically >65%) across a range of scales (0.1-5 mmol). All of the macrocycles reported are efficiently converted (>90%) to rotaxanes under AT-CuAAC conditions. With the requisite macrocycles finally available in sufficient quantities, we further demonstrate their long term utility through the first gram-scale synthesis of an AT-CuAAC [2]rotaxane and extend this powerful methodology to produce novel Sauvage-type molecular shuttles.

| S-EPMC6005271 | biostudies-literature

Synthesis of Porphyrin and Bacteriochlorin Glycoconjugates through CuAAC Reaction Tuning.

Project description:Rapid and reproducible access to a series of unique porphyrin and bacteriochlorin glycoconjugates, including meso-glycosylated porphyrins and bacteriochlorins, and beta-glycosylated porphyrins, via copper catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) is reported for the first time. The work presented highlights the system-dependent reaction conditions required for glycosylation to porphyrins and bacteriochlorins based on the unique electronic properties of each ring system. Attenuated reaction conditions were used to synthesize fifteen new glycosylated porphyrin and bacteriochlorin analogs in 74 - 99% yield, and were extended to solid support to produce the first oligo(amidoamine)-based porphyrin glycoconjugate. These compounds hold significant potential as next generation water soluble catalysts and photodynamic therapy/photodynamic inactivation (PDT/PDI) agents.

| S-EPMC7546392 | biostudies-literature

BTG1 mutation yields super-competitive B cells primed for malignant transformation

Project description:Mutations in the BTG1 tumor suppressor gene are exclusive to germinal center (GC)-derived B cell lymphomas and associate with low clinical outcome. To elucidate the effect of BTG1 mutations in mature B cells, we generated a mouse model for the conditional expression of mutant Btg1 Unlike conventional lymphoma oncogenes, mutated Btg1 expression in B cells did not induce GC hyperplasia. However, placing mutant and wild-type GC B cells in direct competition revealed that mutant Btg1 provides a massive advantage during the GC reaction. Furthermore, mutant Btg1 accelerates and dramatically increases the aggressiveness of BCL2-driven lymphomas in vivo. NGS, cellular and molecular profiling showed activation of Myc and mTORC1 anabolic programs in Btg1 mutant GC B cells, murine lymphomas and patient DLBCLs. These programs characterize T cell-selected GC B cells that enter a growth phase prior to clonal burst. We find that mutant Btg1 sensitizes GC B cells to T cell signals, resulting in a lower threshold to Myc activation, through mRNA translational biochemical mechanisms. Together, we link recurrent mutations of BTG1 to a massive fitness gain of GC B cells that confers an agressive and invasive phenotype to B cell lymphomas in vivo and associate with low clinical outcome in patients with agressive DLBCL. This work reveals a fine-tuned metabolic regulatory network that controls normal GC development and can be hijacked by lymphoma cells during disease progression. These findings have implications for fitness processes and natural selection at a broad level by providing fundamental insight into the power of subtle biochemical shifts to enhance biological fitness of cells.

2023-01-24 | GSE167786 | GEO

Calix[6]arene-Based [3]Rotaxanes as Prototypes for the Template Synthesis of Molecular Capsules.

Project description:In this work, the ability of several bis-viologen axles to thread a series of heteroditopic tris(N-phenylureido)calix[6]arene wheels to give interwoven supramolecular complexes to the [3]pseudorotaxane type was studied. The unidirectionality of the threading process inside these nonsymmetric wheels allows the formation of highly preorganised [3]pseudorotaxane and [3]rotaxane species in which the macrocycles phenylureido moieties, functionalised with either ester, carboxylic, or hydroxymethyl groups, are facing each other. As verified by NMR and semiempirical computational studies, these latter compounds possess the correct spatial arrangement of their subcomponents, which could lead, in principle, upon proper bridging reaction, to the realisation of upper-to-upper molecular capsules that are based on calix[6]arene derivatives.

| S-EPMC9864859 | 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