Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Regio- and stereoselective thiocyanatothiolation of alkynes and alkenes by using NH₄SCN and N-thiosuccinimides.

ABSTRACT: A highly regioselective thiocyanatothiolation of alkynes and alkenes assisted by hydrogen bonding under simple and mild conditions is developed. Our thiocyanatothiolation reagents are readily available ammonium thiocyanate and N-thiosuccinimides. This metal-free system offers good chemical yields for a wide range of alkyne and alkene substrates with good functional group tolerance.

SUBMITTER: Qi L

PROVIDER: S-EPMC9056709 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Regio- and stereoselective thiocyanatothiolation of alkynes and alkenes by using NH4SCN and N-thiosuccinimides.

Qi Liang L Liu Shiwen S Xiao Linxia L

RSC advances 20200910 55

A highly regioselective thiocyanatothiolation of alkynes and alkenes assisted by hydrogen bonding under simple and mild conditions is developed. Our thiocyanatothiolation reagents are readily available ammonium thiocyanate and N-thiosuccinimides. This metal-free system offers good chemical yields for a wide range of alkyne and alkene substrates with good functional group tolerance. ...[more]

PMID: 35515071

Similar Datasets

Regio- and Stereoselective 1,2-Oxyhalogenation of Non-Conjugated Alkynes via Directed Nucleopalladation: Catalytic Access to Tetrasubstituted Alkenes.

Project description:A catalytic 1,2-oxyhalogenation method that converts non-conjugated internal alkynes into tetrasubstituted alkenes with high regio- and stereoselectivity is described. Mechanistically, the reaction involves a PdII /PdIV catalytic cycle that begins with a directed oxypalladation step. The origin of regioselectivity is the preference for formation of a six-membered palladacycle intermediate, which is facilitated by an N,N-bidentate 2-(pyridin-2-yl)isopropyl (PIP) amide directing group. Selectivity for C(alkenyl)-X versus -N (X=halide) reductive elimination from the PdIV center depends on the identity of the halide anion; bromide and iodide engage in C(alkenyl)-X formation, while intramolecular C(alkenyl)-N reductive elimination occurs with chloride to furnish a lactam product. DFT calculations shed light on the origins of this phenomenon.

| S-EPMC9588632 | biostudies-literature

Regio- and Stereoselective Radical Perfluoroalkyltriflation of Alkynes Using Phenyl(perfluoroalkyl)iodonium Triflates.

Project description:A method for regio- and stereoselective anti-addition of the perfluoroalkyl and the triflate group of phenyl(perfluoroalkyl)iodonium triflates to alkynes is presented. The radical reaction uses cheap CuCl as a smart initiator and can be conducted in gram scale. The perfluoroalkyltriflated products are readily further functionalized, rendering this transformation valuable.

| S-EPMC5460293 | biostudies-literature

Highly Efficient Gold(I)-Catalyzed Regio- and Stereoselective Hydrocarboxylation of Internal Alkynes.

Project description:We report the highly efficient gold-catalyzed hydrocarboxylation of internal alkynes that operates under solvent- and silver-free conditions. This new, simple, and eco-friendly protocol allows for the synthesis of a wide variety of functionalized aryl and alkyl enol esters in high yields, with Z-stereospecificity and good regioselectivities and without the requirement for purification by chromatography. This process represents an expedient, operationally simple method for the synthesis of enol esters.

| S-EPMC5745071 | biostudies-literature

Cationic-palladium catalyzed regio- and stereoselective syn-1,2-dicarbofunctionalization of unsymmetrical internal alkynes.

Project description:π-Extended tetrasubstituted olefins are widely found motifs in natural products, leading drugs, and agrochemicals. Thus, development of modular strategies for the synthesis of complex all-carbon-substituted olefins always draws attention. The difunctionalization of unsymmetrical alkynes is an attractive approach but it has remained faced with regioselectivity issues. Here we report the discovery of a regio- and stereoselective syn-1,2-dicarbofunctionalization of unsymmetrical internal alkynes. A cationic Pd-catalyzed three-component coupling of aryl diazonium salts, aryl boronic acids (or olefins) and yne-acetates enables access to all-carbon substituted unsymmetrical olefins. The transformation features broad scope with labile functional group tolerance, building broad chemical space of structural diversity (94 molecules). The value of this synthetic method is demonstrated by the direct transformation of natural products and drug candidates containing yne-acetates, to enable highly substituted structurally complex allyl acetate analogues of biologically important compounds. Synthetic versatility of the carboxylate bearing highly substituted olefins is also presented. The reaction outcome is attributed to the in situ formation of stabilized cationic aryl-Pd species, which regulates regioselective aryl-palladation of unsymmetrical yne-acetates. Control experiments reveal the synergy between the carboxylate protecting group and the cationic Pd-intermediate in the regioselectivity and reaction productivity; density functional theory (DFT) studies rationalize the selectivity of the reaction.

| S-EPMC8927424 | biostudies-literature

Ni-Catalyzed Regio- and Stereoselective Alkylarylation of Unactivated Alkenes in γ,δ-Alkenylketimines.

Project description:We disclose a Ni-catalyzed vicinal alkylarylation of unactivated alkenes in γ,δ-alkenylketimines with aryl halides and alkylzinc reagents. The reaction produces γ-C(sp3)-branched δ-arylketones with the construction of two new C(sp3)-C(sp3) and C(sp3)-C(sp2) bonds. Electron-deficient alkenes play crucial dual roles as ligands to stabilize reaction intermediates and to increase catalytic rates for the formation of C(sp3)-C(sp3) bonds. This alkene alkylarylation reaction is also effective for secondary alkylzinc reagents and internal alkenes, and proceeds with a complete regio- and stereocontrol, affording products with up to three contiguous all-carbon all-cis secondary stereocenters.

| S-EPMC10569404 | biostudies-literature

Highly regio- and stereoselective phosphinylphosphination of terminal alkynes with tetraphenyldiphosphine monoxide under radical conditions.

Project description:The homolytic cleavage of the PV(O)-PIII bond in tetraphenyldiphosphine monoxide simultaneously provides both pentavalent and trivalent phosphorus-centered radicals with different reactivities. The method using V-40 as an initiator is successfully investigated for the regio- and stereoselective phosphinylphosphination of terminal alkynes giving the corresponding trans-isomers of 1-diphenylphosphinyl-2-diphenylthiophosphinyl-1-alkenes in good yields. The protocol can be applied to a wide variety of terminal alkynes including both alkyl- and arylalkynes.

| S-EPMC8077611 | biostudies-literature

Regio- and stereoselective access to highly substituted vinylphosphine oxides via metal-free electrophilic phosphonoiodination of alkynes.

Project description:In general, the P-centered ring-opening of quaternary phosphirenium salts (QPrS) predominantly leads to hydrophosphorylated products, while the C-centered ring-opening is primarily confined to intramolecular nucleophilic reactions, resulting in the formation of phosphorus-containing cyclization products instead of difunctionalized products generated through intermolecular nucleophilic processes. Here, through the promotion of ring-opening of three-member rings by iodine anions and the quenching of electronegative carbon atoms by iodine cations, we successfully synthesize β-functionalized vinylphosphine oxides by the P-addition of QPrS intermediates generated in situ. Multiple β-iodo-substituted vinylphosphine oxides can be obtained with exceptional regio- and stereo-selectivity by reacting secondary phosphine oxides with unactivated alkynes. In addition, a variety of β-functionalized vinylphosphine oxides converted from C-I bonds, especially the rapid construction of benzo[b]phospholes oxides, demonstrates the significance of this strategy.

| S-EPMC11199708 | biostudies-literature

Copper-Metallized Porous N-Heterocyclic Carbene Ligand Polymer-Catalyzed Regio- and Stereoselective 1,2-Carboboration of Alkynes.

Project description:Alkenylboronates are highly versatile building blocks and valuable reagents in the synthesis of complex molecules. Compared with that of monosubstituted alkenylboronates, the synthesis of multisubstituted alkenylboronates is challenging. The copper-catalyzed carboboration of alkynes is an operationally simple and straightforward method for synthesizing bis/trisubstituted alkenylboronates. In this work, a series of copper-metallized N-Heterocyclic Carbene (NHC) ligand porous polymer catalysts are designed and synthesized in accordance with the mechanism of carboboration. By using CuCl@POL-NHC-Ph as the optimal nanocatalyst, this study realizes the β-regio- and stereoselective (syn-addition) 1,2-carboboration of alkynes (regioselectivity up to >99:1) with satisfactory yields and a wide range of substrates. This work not only overcomes the selectivity of carboboration but also provides a new strategy for the design of nanocatalysts and their application in organic synthesis.

| S-EPMC10870022 | biostudies-literature

Regio- and Stereoselective Allylindation of Alkynes Using InBr₃ and Allylic Silanes: Synthesis, Characterization, and Application of 1,4-Dienylindiums toward Skipped Dienes.

Project description:Regioselective anti-allylindation of alkynes was achieved using InBr₃ and allylic silanes. Various types of alkynes and allylic silanes were applicable to the present allylindation. This sequential process used the generated 1,4-dienylindiums to establish novel synthetic methods for skipped dienes. The 1,4-dienylindiums were characterized by spectral analysis and treated with I₂ to stereoselectively give 1-iodo-1,4-dienes. The Pd-catalyzed cross coupling of 1,4-dienylindium with iodobenzene successfully proceeded in a one-pot manner to afford the corresponding 1-aryl-1,4-diene.

| S-EPMC6222668 | biostudies-literature

Solubility of sulfur dioxide in tetraglyme-NH4SCN ionic liquid: high absorption efficiency.

Project description:An easily prepared ionic liquid was synthesized by a one-step method and applied in SO2 absorption efficiently. The cation of the ionic liquid is a supramolecular structure consisting of NH+ 4 and tetraglyme, similar to the structure of NH+ 4 and crown ether, and the anion is selected as SCN-. The ionic liquid has good thermal stability. Under the conditions of 293 K and 1 bar, one mol ionic liquid can absorb 2.73 mol SO2, which is about 30% higher than tetraglyme. The absorption mechanism was characterized using IR and NMR. And the results confirmed that the interaction mechanism between SO2 and the ionic liquid is a physical interaction rather than a chemical interaction.

| S-EPMC9092115 | biostudies-literature