Browse
Submit Data
Databases
API
Help

Dataset Information

19 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Non-C2-Symmetric Bis-Benzimidazolium Salt Applied in the Synthesis of Sterically Hindered Biaryls

ABSTRACT: A novel non-C2-symmetric bis-benzimidazolium salt derived from (±)-valinol has been prepared by a simple and straightforward process in good yield. The structure of bis-benzimidazolium salt provided a bulky steric group on the ethylene bridge; which facilitates the catalytic efficacy in the C(sp2)–C(sp2) formation. Its catalytic activity in Suzuki–Miyaura cross-coupling reaction of unactivated aryl chlorides has been found to have high efficacy in 1 mol% Pd loading. This protocol demonstrated the potential on the synthesis of sterically hindered biaryls.

SUBMITTER: Chen Y

PROVIDER: S-EPMC8588361 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Self-interrupted synthesis of sterically hindered aliphatic polyamide dendrimers.

Project description:2,2-Bis(azidomethyl)propionic acid was prepared in four steps and 85% yield from the commercially available 2,2-bis(hydroxymethyl)propionic acid and used as the starting building block for the divergent, convergent, and double-stage convergent-divergent iterative methods for the synthesis of dendrimers and dendrons containing ethylenediamine (EDA), piperazine (PPZ), and methyl 2,2-bis(aminomethyl)propionate (COOMe) cores. These cores have the same multiplicity but different conformations. A diversity of synthetic methods were used for the synthesis of dendrimers and dendrons. Regardless of the method used, a self-interruption of the synthesis was observed at generation 4 for the dendrimer with an EDA core and at generation 5 for the one with a PPZ core, whereas for the COOMe core, self-interruption was observed at generation 6 dendron, which is equivalent to generation 5 dendrimer. Molecular modeling and molecular-dynamics simulations demonstrated that the observed self-interruption is determined by the backfolding of the azide groups at the periphery of the dendrimer. The latter conformation inhibits completely the heterogeneous hydrogenation of the azide groups catalyzed by 10% Pd/carbon as well as homogeneous hydrogenation by the Staudinger method. These self-terminated polyamide dendrimers are enzymatically and hydrolytically stable and also exhibit antimicrobial activity. Thus, these nanoscale constructs open avenues for biomedical applications.

| S-EPMC5373347 | biostudies-literature

Practical Organocatalytic Synthesis of Functionalized Non-C2-Symmetrical Atropisomeric Biaryls.

Project description:An organic acid catalyzed direct arylation of aromatic C(sp(2))-H bonds in phenols and naphthols for the preparation of 1,1'-linked functionalized biaryls was developed. The products are non-C2-symmetrical, atropoisomeric, and represent previously untapped chemical space. Overall this transformation is operationally simple, does not require an external oxidant, is readily scaled up (up to 98?mmol), and the structurally diverse 2,2'-dihydroxy biaryl (i.e., BINOL-type), as well as 2-amino-2'-hydroxy products (i.e., NOBIN-type) are formed with complete regioselectivity. Density-functional calculations suggest that the quinone and imino-quinone monoacetal coupling partners are exclusively arylated at their ?-position by an asynchronous [3,3]-sigmatropic rearrangement of a mixed acetal species which is formed in?situ under the reaction conditions.

| S-EPMC4824624 | biostudies-literature

Ferrocene-Containing Sterically Hindered Phosphonium Salts.

Project description:The synthesis and physical properties of the series of the ferrocenyl-containing sterically hindered phosphonium salts based on di(tert-butyl)ferrocenylphosphine is reported. Analysis of voltamogramms of the obtained compounds revealed some correlations between their structures and electrochemical properties. The elongation of the alkyl chain at the P atom as well as replacement of the Br- anion by [BF?]- shifts the ferrocene/ferrocenium transition of the resulting salts into the positive region. DFT results shows that in the former case, the Br- anion destabilizes the corresponding ion pair, making its oxidation easier due to increased highest occupied molecular orbital (HOMO) energy. Increased HOMO energy for ion pairs with the Br- ion compared to BF?- are caused by contribution of bromide atomic orbitals to the HOMO. The observed correlations can be used for fine-tuning the properties of the salts making them attractive for applications in multicomponent batteries and capacitors.

| S-EPMC6278326 | biostudies-literature

Cu-catalyzed arylation of phenols: synthesis of sterically hindered and heteroaryl diaryl ethers.

Project description:Cu-catalyzed O-arylation of phenols with aryl iodides and bromides can be performed under mild condition in DMSO/K(3)PO(4) with use of picolinic acid as the ligand for copper. This method tolerates a variety of functional groups and is effective in the synthesis of hindered diaryl ethers and heteroaryl ethers.

| S-EPMC3142471 | biostudies-literature

Enhanced clickability of doubly sterically-hindered aryl azides.

Project description:Steric character is one of the most fundamental factors to determine the reactivity of the substrate in organic synthesis. In bimolecular reaction, the sterically-bulky group situated close to the reactive center generally prevents the approach of the reaction partner retarding the bond formation. This report describes, to the contrary, significantly enhanced reactivity of 2,6-disubstituted phenyl azides observed in catalyst-free 1,3-dipolar cycloaddition with alkynes, unexpectedly reacting faster than unsubstituted phenyl azide and even more faster than unhindered alkyl azide, despite the steric hindrance adjacent to the reactive azido group. Experimental and computational studies have indicated that the steric hindrance eliciting the inhibition of resonance between azido group and the aromatic ring is the primary cause of this apparently-paradoxical phenomenon. This is the first type of steric acceleration, indicating a possibility of designing a highly reactive functional group by strategically locating it in the sterically-congested environment.

| S-EPMC3216569 | biostudies-literature

Flow carbonylation of sterically hindered ortho-substituted iodoarenes.

Project description:The flow synthesis of ortho-substituted carboxylic acids, using carbon monoxide gas, has been studied for a number of substrates. The optimised conditions make use of a simple catalyst system compromising of triphenylphosphine as the ligand and palladium acetate as the pre-catalyst. Carbon monoxide was introduced via a reverse "tube-in-tube" flow reactor at elevated pressures to give yields of carboxylated products that are much higher than those obtained under normal batch conditions.

| S-EPMC4979912 | biostudies-literature

Carbonylative cross-coupling of ortho-disubstituted aryl iodides. convenient synthesis of sterically hindered aryl ketones.

Project description:A mild and general protocol for the carbonylative cross-coupling of sterically hindered ortho-disubstituted aryl iodides is reported. Carbonylative Suzuki-Miyaura couplings of a variety of aryl boronic acids provide an array of substituted biaryl ketones in modest to excellent yield. A carbonylative Negishi coupling that utilizes alkynyl nucleophiles is also described.

| S-EPMC2636973 | biostudies-literature

Cu-Catalyzed C-N Coupling with Sterically Hindered Partners.

Project description:Copper, an earth-abundant metal, has reemerged as a viable alternative to the versatile Pd-catalyzed C-N coupling. Coupling sterically hindered reaction partners, however, remains challenging. Herein, we disclose the discovery and development of a pyrrole-ol ligand to facilitate the coupling of ortho-substituted aryl iodides with sterically hindered amines. The ligand was discovered through a library screening approach and highlights the value of mining heteroatom-rich pharmaceutical libraries for useful ligand motifs. Further evaluation revealed that this ligand is uniquely effective in these challenging transformations. The reaction enables the coupling of sterically hindered primary and secondary amines, anilines, and amides with broad functional group tolerance.

| S-EPMC10104551 | biostudies-literature

Synthesis of sterically hindered 4,5-diarylphenanthrenes <i>via</i> acid-catalyzed bisannulation of benzenediacetaldehydes with alkynes.

Project description:The synthesis of sterically hindered phenanthrenes via acid-catalyzed bisannulation reaction is described. Treatment of 1,4-benzenediacetaldehyde with terminal aryl alkynes in the presence of B(C6F5)3 provides 4,5-diarylphenanthrenes in good yields with excellent regioselectivity. The use of internal alkyne substrates enabled the synthesis of sterically hindered 3,4,5,6-tetrasubstituted phenanthrenes displaying augmented backbone helicity. Furthermore, 1,5-disubstituted, 1,8-disubstituted, 1,2,5,6-tetrasubstituted, and 1,2,7,8-tetrasubstituted phenanthrenes can be obtained through the reaction of alkynes with 1,3-benzenediacetaldehyde or 1,2-benzenediacetaldehyde disilyl acetal.

| S-EPMC6552489 | biostudies-literature

Design, synthesis, and biological activity of novel ammonium salts containing sterically hindered phenolic fragment and phosphoryl group.

Project description:Here, we present an approach to novel "hybrid" biologically active compounds based on a combination of sterically hindered phenol and ammonium pharmacophores in a single molecule. The novel target ammonium salts were obtained by the reaction of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-N-(2-(dimethylamino)alkyl)propanamide with aliphatic bromides or by the reaction of phosphorylated methylenequinones with diamines followed by alkylation with organic bromides. A series of twenty-three novel multifunctional ammonium salts that contain a sterically hindered phenolic fragment were assessed for antimicrobial, cytotoxic and antioxidant activity. The compounds exhibited antimicrobial activity against Staphylococcus aureus ATCC 209p, Bacillus cereus ATCC 8035, Escherichia coli CDC F-50, Pseudomonas aeruginosa ATCC 9027, Aspergillus niger BKMF-1119, Trichophyton mentagrophytes var. gypseum 1773, and Candida albicans 855-653 in the concentration range of 442-0.70 μM. The maximum activity of an ammonium salt among all the types of structure was observed in cases in which a decyl radical was present on the onium nitrogen atom. The most active compounds exhibited antioxidant activity at levels of 0.25 and 0.50 mM and did not display cytotoxic properties towards WI-38 (human embryonic lung cells) and Chang liver (human liver cells) cell lines in the concentration range of 0.70-11.3 μM.

| S-EPMC6335997 | 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