Browse
Submit Data
Databases
API
Help

Dataset Information

17 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Direct Synthesis of 5-Aryl Barbituric Acids by Rhodium(II)-Catalyzed Reactions of Arenes with Diazo Compounds.

ABSTRACT: A commercially available rhodium(II) complex catalyzes the direct arylation of 5-diazobarbituric acids with arenes, allowing straightforward access to 5-aryl barbituric acids. Free N-H groups are tolerated on the barbituric acid, with no complications arising from N-H insertion processes. This method was applied to the concise synthesis of a potent matrix metalloproteinase (MMP) inhibitor.

SUBMITTER: Best D

PROVIDER: S-EPMC4479025 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Direct Synthesis of 5-Aryl Barbituric Acids by Rhodium(II)-Catalyzed Reactions of Arenes with Diazo Compounds.

Best Daniel D Burns David J DJ Lam Hon Wai HW

Angewandte Chemie (International ed. in English) 20150508 25

A commercially available rhodium(II) complex catalyzes the direct arylation of 5-diazobarbituric acids with arenes, allowing straightforward access to 5-aryl barbituric acids. Free N-H groups are tolerated on the barbituric acid, with no complications arising from N-H insertion processes. This method was applied to the concise synthesis of a potent matrix metalloproteinase (MMP) inhibitor. ...[more]

PMID: 25959544

Similar Datasets

Triarylborane-Catalyzed Alkenylation Reactions of Aryl Esters with Diazo Compounds.

Project description:Herein we report a facile, mild reaction protocol to form carbon-carbon bonds in the absence of transition metal catalysts. We demonstrate the metal-free alkenylation reactions of aryl esters with ?-diazoesters to give highly functionalized enyne products. Catalytic amounts of tris(pentafluorophenyl)borane (10-20?mol?%) are employed to afford the C=C coupled products (31 examples) in good to excellent yields (36-87?%). DFT studies were used to elucidate the mechanism for this alkenylation reaction.

| S-EPMC7497215 | biostudies-literature

Rhodium-catalyzed intramolecular C-H insertion of alpha-aryl-alpha-diazo ketones.

Project description:Direct diazo transfer proceeds smoothly with alpha-aryl ketones. The derived alpha-aryl-alpha-diazo ketones cyclize efficiently with Rh catalysis to give the corresponding alpha-aryl cyclopentanones.

| S-EPMC3248813 | biostudies-literature

Biaryl Formation via Base-Promoted Direct Coupling Reactions of Arenes with Aryl Halides.

Project description:In the absence of ligand, Cs2CO3-promoted cross-coupling reaction of arenes with cyano-/nitro-substituted aryl halides in DMSO affording biaryls is reported. The cyano/nitro group in biaryls is useful and convenient for further transformation. The formation of dibenzofurans resulting from the reactions between arenes and 1-bromo-2-iodobenzene is also reported. On the basis of control experiments and theoretical studies, a radical mechanism is proposed for the formation of biaryls.

| S-EPMC8223439 | biostudies-literature

Rhodium-catalyzed asymmetric 1,4-addition reactions of aryl boronic acids with nitroalkenes: reaction mechanism and development of homogeneous and heterogeneous catalysts.

Project description:Asymmetric 1,4-addition reactions with nitroalkenes are valuable because the resulting chiral nitro compounds can be converted into various useful species often used as chiral building blocks in drug and natural product synthesis. In the present work, asymmetric 1,4-addition reactions of arylboronic acids with nitroalkenes catalyzed by a rhodium complex with a chiral diene bearing a tertiary butyl amide moiety were developed. Just 0.1 mol% of the chiral rhodium complex could catalyze the reactions and give the desired products in high yields with excellent enantioselectivities. The homogeneous catalyst thus developed could be converted to a reusable heterogeneous metal nanoparticle system using the same chiral ligand as a modifier, which was immobilized using a polystyrene-derived polymer with cross-linking moieties, maintaining the same level of enantioselectivity. To our knowledge, this is the first example of asymmetric 1,4-addition reactions of arylboronic acids with nitroalkenes in a heterogeneous system. Wide substrate generality and high catalytic turnover were achieved in the presence of sufficient water without any additives such as KOH or KHF2 in both homogeneous and heterogeneous systems. Various insights relating to a rate-limiting step in the catalytic cycle, the importance of water, role of the secondary amide moiety in the ligand, and active species in the heterogeneous system were obtained through mechanistic studies.

| S-EPMC5863615 | biostudies-literature

Rhodium(II)-catalyzed asymmetric sulfur(VI) reduction of diazo sulfonylamidines.

Project description:Diazo sulfonylamidines readily undergo enantioselective oxygen transfer from sulfur to carbon atom in the presence of chiral rhodium(II) carboxylates resulting in chiral sulfinylamidines. This unusual asymmetric atom transfer "reduction" occurs rapidly under mild conditions, and sulfinylamidines are obtained in excellent yield.

| S-EPMC3627535 | biostudies-literature

Rhodium-catalyzed cascade reactions of triazoles with organoselenium compounds - a combined experimental and mechanistic study.

Project description:Herein, we report on our studies on the reaction of organoselenium compounds with triazoles under thermal conditions using simple Rh(ii) catalysts. These reactions do not provide the product of classic rearrangement reactions. Instead two different cascade reactions were uncovered. While allyl selenides react in a cascade of sigmatropic rearrangement and selenium-mediated radical cyclization reaction to give dihydropyrroles, cinnamyl selenides undergo a double rearrangement reaction cascade involving a final aza-Cope reaction to give the product of 1,3-difunctionalization. Theoretical and experimental studies were conducted to provide an understanding of the reaction mechanism of these cascade reactions. The former provide an important insight into fundamental question on the nature of the ylide intermediate in rearrangement reactions and reveal that organoselenium compounds take up multiple roles in rearrangement reactions and mediate a free ylide reaction mechanism.

| S-EPMC8115268 | biostudies-literature

A Versatile Route to Unstable Diazo Compounds via Oxadiazolines and their Use in Aryl-Alkyl Cross-Coupling Reactions.

Project description:Coupling of readily available boronic acids and diazo compounds has emerged recently as a powerful metal-free carbon-carbon bond forming method. However, the difficulty in forming the unstable diazo compound partner in a mild fashion has hitherto limited their general use and the scope of the transformation. Here, we report the application of oxadiazolines as precursors for the generation of an unstable family of diazo compounds using flow UV photolysis and their first use in divergent protodeboronative and oxidative C(sp2 )-C(sp3 ) cross-coupling processes, with excellent functional-group tolerance.

| S-EPMC5814725 | biostudies-literature

Higher-Order Cyclopropenimine Superbases: Direct Neutral Bronsted Base Catalyzed Michael Reactions with ?-Aryl Esters.

Project description:The synthesis and characterization of six new classes of higher-order superbases, including five that incorporate cyclopropenimine functionality, has been achieved. We propose a nomenclature that designates these as the CG2, GC2, PC3, PC1, C3, and GP2 classes of superbases. The pK(BH+) values were measured to be between 29.0 and 35.6 in acetonitrile. Linear correlations of ten superbase basicities vs that of their substituents demonstrated the insulating effect of the cyclopropenimine core. The molecular structures of several of these materials were obtained by single-crystal X-ray analysis, revealing interesting aspects of conformational bias and noncovalent organization. The types of superbasic cores and substituents were each reliably shown to affect selectivity for deprotonation over alkylation. Higher-order cyclopropenimine and guanidine superbase stability to hydrolysis was found to correlate to basicity. Finally, a GC2 base was found to catalyze conjugate additions of ?-aryl ester pronucleophiles, representing the first report of a neutral Brønsted base to catalyze such reactions.

| S-EPMC4617652 | biostudies-literature

Rhodium-Catalyzed C-H Methylation and Alkylation Reactions by Carbene-Transfer Reactions.

Project description:In this combined computational and experimental study, the C-H functionalization of 2-phenyl pyridine with diazoalkanes was investigated. Initial evaluation by computational methods allowed the evaluation of different metal catalysts and diazoalkanes and their compatibility in this C-H functionalization reaction. With these findings, suitable reaction conditions for the C-H methylation reactions were quickly identified by using highly reactive TMS diazomethane and C-H alkylation reactions with donor/acceptor diazoalkanes, which is applied to a broad scope on alkylation reactions of 2-aryl pyridines with TMS diazomethane and donor/acceptor diazoalkane (51 examples, up to 98 % yield).

| S-EPMC9302633 | biostudies-literature

Copper-catalyzed oxidative Heck reactions between alkyltrifluoroborates and vinyl arenes.

Project description:We report herein that potassium alkyltrifluoroborates can be utilized in oxidative Heck-type reactions with vinyl arenes. The reaction is catalyzed by a Cu(OTf)2/1,10-phenanthroline with MnO2 as the stoichiometric oxidant. In addition to the alkyl Heck, amination, esterification, and dimerization reactions of alkyltrifluoroborates are demonstrated under analogous reaction conditions. Evidence for an alkyl radical intermediate is presented.

| S-EPMC3978782 | biostudies-literature

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