Browse
Submit Data
Databases
API
Help

Dataset Information

20 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Copper-Catalyzed Coupling of Thioamides and Donor/Acceptor-Substituted Carbenoids: Synthesis of Enamino Esters and Enaminones.

ABSTRACT: The coupling of thioamides and donor/acceptor-substituted diazocarbonyl compounds is reported for the first time. The present report provides a mild, catalytic method that couples thioamides and donor/acceptor-substituted diazocarbonyl compounds to form enamino esters and enaminones. Unlike traditional methods for the synthesis of enamino esters and enaminones from thioamides, both N-alkyl thioamides and thiocarbamates are suitable substrates in this coupling reaction. Copper(I) bromide catalyzes the reaction and provides enamino esters and enaminones chemo- and diastereoselectively in less time than Rh₂(OAc)₄ or Ru(PPh₃)₃Cl₂ catalysts.

SUBMITTER: Pal A

PROVIDER: S-EPMC6648369 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Copper-Catalyzed Coupling of Thioamides and Donor/Acceptor-Substituted Carbenoids: Synthesis of Enamino Esters and Enaminones.

Pal Arpan A Hussaini Syed Raziullah SR

ACS omega 20190104 1

The coupling of thioamides and donor/acceptor-substituted diazocarbonyl compounds is reported for the first time. The present report provides a mild, catalytic method that couples thioamides and donor/acceptor-substituted diazocarbonyl compounds to form enamino esters and enaminones. Unlike traditional methods for the synthesis of enamino esters and enaminones from thioamides, both N-alkyl thioamides and thiocarbamates are suitable substrates in this coupling reaction. Copper(I) bromide catalyze ...[more]

PMID: 31459329

Similar Datasets

Selective Coupling of 1,2-Bis-Boronic Esters at the more Substituted Site through Visible-Light Activation of Electron Donor-Acceptor Complexes.

Project description:1,2-Bis-boronic esters are useful synthetic intermediates particularly as the two boronic esters can be selectively functionalized. Usually, the less hindered primary boronic ester reacts, but herein, we report a coupling reaction that enables the reversal of this selectivity. This is achieved through the formation of a boronate complex with an electron-rich aryllithium which, in the presence of an electron-deficient aryl nitrile, leads to the formation of an electron donor-acceptor complex. Following visible-light photoinduced electron transfer, a primary radical is generated which isomerizes to the more stable secondary radical before radical-radical coupling with the arene radical-anion, giving β-aryl primary boronic ester products. The reactions proceed under catalyst-free conditions. This method also allows stereodivergent coupling of cyclic cis-1,2-bis-boronic esters to provide trans-substituted products, complementing the selectivity observed in the Suzuki-Miyaura reaction.

| S-EPMC9314813 | biostudies-literature

Palladium-Catalyzed Cascade to Benzoxepins by Using Vinyl-Substituted Donor-Acceptor Cyclopropanes.

Project description:A palladium-catalyzed intermolecular cascade (4+3) cyclocondensation of salicylaldehydes and vinylcyclopropanes is reported. A key feature of the reaction is the use of a phosphonate group as an acceptor moiety on the cyclopropane, exploiting its propensity to undergo olefination with aldehydes. Subsequent O-allylation enabled the formation of a range of substituted benzoxepinsWith a novel chiral ligand, the products were obtained in generally good yield and with reasonable enantioselectivity.

| S-EPMC8251625 | biostudies-literature

Palladium-catalyzed Suzuki-Miyaura coupling of thioureas or thioamides.

Project description:Cross-coupling reactions involving metal carbene intermediates play an increasingly important role in C-C bond formation. Expanding the carbene precursors to a broader range of starting materials and more diverse products is an ongoing challenge in synthetic organic chemistry. Herein, we report a Suzuki-Miyaura coupling reaction of in situ-generated Pd-carbene complexes via desulfurization of thioureas or thioamides. This strategy enables the preparation of a broad array of substituted amidinium salts and unsymmetrical diaryl ketones. The reaction is readily scalable, compatible with bromo groups on aromatic rings, tolerant to moisture and air and has a broad substrate scope. Furthermore, a single crystal structure of Pd-diaminocarbene complex is obtained and proven to be the key intermediate in both catalytic and stoichiometric reactions. Preliminary mechanistic studies demonstrate the dual role of the silver salt as a desulfurating reagent assisting the elimination of sulfur and as oxidant facilitating the PdII/Pd0/PdII catalytic cycle.

| S-EPMC6911099 | biostudies-literature

Acetoxy-Substituted Cyclopropane Dicarbonyls as Stable Donor-Acceptor-Acceptor Cyclopropanes.

Project description:A study of cyclopropanations of oxy-substituted ethenes with ethyl ?-diazoaroyl acetates is described. Whereas trimethylsilyl vinyl ether and ethyl vinyl ether gave dihydrofuran products, stable cyclopropanes were isolated when vinyl acetate was used. Yields ranged from 0-87%, depending on the nature and position of the aryl ring substituent.

| S-EPMC4852370 | biostudies-literature

Copper-Catalyzed Oxidative Cross-Coupling of Electron-Deficient Polyfluorophenylboronate Esters with Terminal Alkynes.

Project description:We report herein a mild procedure for the copper-catalyzed oxidative cross-coupling of electron-deficient polyfluorophenylboronate esters with terminal alkynes. This method displays good functional group tolerance and broad substrate scope, generating cross-coupled alkynyl(fluoro)arene products in moderate to excellent yields. Thus, it represents a simple alternative to the conventional Sonogashira reaction.

| S-EPMC7821263 | biostudies-literature

Highly stereoselective C-C bond formation by rhodium-catalyzed tandem ylide formation/[2,3]-sigmatropic rearrangement between donor/acceptor carbenoids and chiral allylic alcohols.

Project description:The tandem ylide formation/[2,3]-sigmatropic rearrangement between donor/acceptor rhodium carbenoids and chiral allyl alcohols is a convergent C-C bond forming process, which generates two vicinal stereogenic centers. Any of the four possible stereoisomers can be selectively synthesized by appropriate combination of the chiral catalyst Rh(2)(DOSP)(4) and the chiral alcohol.

| S-EPMC3413634 | biostudies-literature

Copper-catalyzed cascade reactions of ?,?-unsaturated esters with keto esters.

Project description:A copper-catalyzed cascade reaction of ?,?-unsaturated esters with keto esters is reported. It features a copper-catalyzed reductive aldolization followed by a lactonization. This method provides a facile approach to prepare ?-carboxymethyl-?-lactones and ?-carboxymethyl-?-lactones under mild reaction conditions.

| S-EPMC4362015 | biostudies-literature

Donor-Acceptor Substituted Benzo-, Naphtho- and Phenanthro-Fused Norbornadienes.

Project description:The photochromic norbornadiene/quadricyclane (NBD/QC) couple has found interest as a molecular solar thermal energy (MOST) system for storage of solar energy. To increase the energy difference between the two isomers, we present here the synthesis of a selection of benzo-fused NBD derivatives that contain an aromatic unit, benzene, naphthalene or phenanthrene, fused to one of the NBD double bonds, while the carbon atoms of the other double bond are functionalized with donor and acceptor groups. The synthesis protocols involve functionalization of benzo-fused NBDs with bromo/chloro substituents followed by a subjection of these intermediates to a cyanation reaction (introducing a cyano acceptor group) followed by a Sonogashira coupling (introducing an arylethynyl donor group, -CCC6H4NMe2 or -CCC6H4OMe). While the derivatives have good absorption properties in the visible region (redshifted relative to parent system) in the context of MOST applications, they lack the ability to undergo NBD-to-QC photoisomerization, even in the presence of a photosensitizer. It seems that loss of aromaticity of the fused aromatics is too significant to allow photoisomerization to occur. The concept of destroying aromaticity of a neighboring moiety as a way to enhance the energy density of the NBD/QC couple thus needs further structural modifications, in the quest for optimum MOST systems.

| S-EPMC7024342 | biostudies-literature

Nickel-Catalyzed Anionic Cross-Coupling Reaction of Lithium Sulfonimidoyl Alkylidene Carbenoids With Organolithiums.

Project description:The mechanistic platform for a novel nickel0 -catalyzed anionic cross-coupling reaction (ACCR) of lithium sulfonimidoyl alkylidene carbenoids (metalloalkenyl sulfoximines) with organometallic reagents is reported herein, affording substituted alkenylmetals and lithium sulfinamides. The Ni0 -catalyzed ACCR of three different types of metalloalkenyl sulfoximines, including acyclic, axially chiral and exocyclic derivatives, with sp2 organolithiums and sp2 and sp3 Grignard reagents has been studied. The ACCR of metalloalkenyl sulfoximines with PhLi in the presence of the Ni0 -catalyst and precatalyst Ni(PPh3 )2 Cl2 afforded alkenyllithiums, under inversion of configuration at the C atom and complete retention at the S atom. In a combination of experimental and DFT studies, we propose a catalytic cycle of the Ni0 -catalyzed ACCR of lithioalkenyl sulfoximines. Computational studies reveal two distinctive pathways of the ACCR, depending on whether a phosphine or 1,5-cyclooctadiene (COD) is the ligand of the Ni atom. They rectify the underlying importance of forming the key Ni0 -vinylidene intermediate through an indispensable electron-rich Ni0 -center coordinated by phosphine ligands. Fundamentally, we present a mechanistic study in controlling the diastereoselectivity of the alkenyllithium formation via the key lithium sulfinamide coordinated Ni0 -vinylidene complex, which consequently avoids an unselective formation of an alkylidene carbene Ni-complex and ultimately racemic alkenyllithium.

| S-EPMC7079181 | biostudies-literature

Scope and mechanistic analysis of the enantioselective synthesis of allenes by rhodium-catalyzed tandem ylide formation/[2,3]-sigmatropic rearrangement between donor/acceptor carbenoids and propargylic alcohols.

Project description:Rhodium-catalyzed reactions of tertiary propargylic alcohols with methyl aryl- and styryldiazoacetates result in tandem reactions, consisting of oxonium ylide formation followed by [2,3]-sigmatropic rearrangement. This process competes favorably with the standard O-H insertion reaction of carbenoids. The resulting allenes are produced with high enantioselectivity (88-98% ee) when the reaction is catalyzed by the dirhodium tetraprolinate complex, Rh(2)(S-DOSP)(4). Kinetic resolution is possible when racemic tertiary propargylic alcohols are used as substrates. Under the kinetic resolution conditions, the allenes are formed with good diastereoselectivity and enantioselectivity (up to 6.1:1 dr, 88-93% ee), and the unreacted alcohols are enantioenriched to 65-95% ee. Computational studies reveal that the high asymmetric induction is obtained via an organized transition state involving a two-point attachment: ylide formation between the alcohol oxygen and the carbenoid and hydrogen bonding of the alcohol to a carboxylate ligand. The 2,3-sigmatropic rearrangement proceeds through initial cleavage of the O-H bond to generate an intermediate with close-lying open-shell singlet, triplet, and closed-shell singlet electronic states. This intermediate would have significant diradical character, which is consistent with the observation that the 2,3-sigmatropic rearrangement is favored with donor/acceptor carbenoids and more highly functionalized propargylic alcohols.

| S-EPMC3549399 | 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