Browse
Submit Data
Databases
API
Help

Dataset Information

21 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Enantioselective Cascade Cyclization/Protodemetalation of Polyenes with N3Pt(2+) Catalysts.

ABSTRACT: The combination of the N-based pincer ligand PyBOX with Pt(2+) leads to new catalysts for the enantioselective cycloisomerization of dienyl- and trienyl-ols. The mechanistic combination of electrophilic cyclization followed by rapid protodemetalation is surprising and leads to a powerful construct for developing new reactions.

SUBMITTER: Nguyen H

PROVIDER: S-EPMC4372115 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Enantioselective Cascade Cyclization/Protodemetalation of Polyenes with N3Pt2+ Catalysts.

Nguyen Ha H Gagné Michel R MR

ACS catalysis 20140203 3

The combination of the N-based pincer ligand PyBOX with Pt2+ leads to new catalysts for the enantioselective cycloisomerization of dienyl- and trienyl-ols. The mechanistic combination of electrophilic cyclization followed by rapid protodemetalation is surprising and leads to a powerful construct for developing new reactions. ...[more]

PMID: 25838970

Similar Datasets

Catalytic enantioselective cyclization and C3-fluorination of polyenes.

Project description:(Xylyl-phanephos)Pt(2+) in combination with XeF(2) mediates the consecutive diastereoselective cation-olefin cyclization/fluorination of polyene substrates. Isolated yields were typically in the 60-69% range while enantioselectivities reached as high as 87%. The data are consistent with a stereoretentive fluorination of a P(2)Pt-alkyl cation intermediate.

| S-EPMC3552331 | biostudies-literature

Asymmetric oxidative cation/olefin cyclization of polyenes: evidence for reversible cascade cyclization.

Project description: Not available

| S-EPMC2908993 | biostudies-literature

Chiral Brønsted Acid Catalyzed Cascade Alcohol Deprotection and Enantioselective Cyclization

Project description: Not available

| S-EPMC10795110 | biostudies-literature

Enantioselective copper-catalyzed construction of aryl pyrroloindolines via an arylation-cyclization cascade.

Project description:An enantioselective arylation-cyclization cascade has been accomplished using a combination of diaryliodonium salts and asymmetric copper catalysis. These mild catalytic conditions provide a new strategy for the enantioselective construction of pyrroloindolines, an important alkaloid structural motif that is commonly found among biologically active natural products.

| S-EPMC3392034 | biostudies-literature

Gold and BINOL-phosphoric acid catalyzed enantioselective hydroamination/N-sulfonyliminium cyclization cascade.

Project description:A highly enantioselective hydroamination/N-sulfonyliminium cyclization cascade is reported using a combination of gold(I) and chiral phosphoric acid catalysts. An initial 5-exo-dig hydroamination and a subsequent phosphoric acid catalyzed cyclization process provide access to complex sulfonamide scaffolds in excellent yield and high enantiocontrol. The method can be extended to lactam derivatives, with excellent yields and enantiomeric excesses of up to 93% ee.

| S-EPMC3931332 | biostudies-literature

Enantioselective, Lewis Base-Catalyzed Sulfenocyclization of Polyenes.

Project description:A sulfenium-ion-initiated, catalytic, enantioselective polyene cyclization is described. Homogeranylarenes and ortho-geranylphenols undergo polycyclization in good yield, diastereoselectivity, and enantioselectivity. The stereodetermining step is the generation of an enantiomerically enriched thiiranium ion from a terminal alkene and a sulfenylating agent in the presence of a chiral Lewis basic catalyst. The use of hexafluoroisopropyl alcohol as the solvent is crucial to obtain good yields. The thioether moiety resulting from the reaction can be subsequently transformed into diverse oxygen and carbon functionality postcyclization. The utility of this method is demonstrated by the enantioselective syntheses of (+)-ferruginol and (+)-hinokiol.

| S-EPMC6008787 | biostudies-literature

Diastereoselective Pt catalyzed cycloisomerization of polyenes to polycycles.

Project description:Application of a tridentate NHC containing pincer ligand to Pt catalyzed cascade cyclization reactions has allowed for the catalytic, diastereoselective cycloisomerization of biogenic alkene terminated substrates to the their polycyclic counterparts.

| S-EPMC3985707 | biostudies-literature

Enantioselective organocatalytic construction of pyrroloindolines by a cascade addition-cyclization strategy: synthesis of (-)-flustramine B.

Project description:Pyrroloindoline and bispyrroloindoline are a subclass of alkaloid structural motifs that commonly exhibit biological activity. An enantioselective organocatalytic approach to the synthesis of pyrroloindoline architecture is described. The addition-cyclization of tryptamines with alpha,beta-unsaturated aldehydes in the presence of imidazolidinone catalysts 1 and 8 provides pyrroloindoline adducts in high yield and excellent enantioselectivities. This transformation is successful for a wide range of tryptamine and alpha,beta-unsaturated aldehyde substrates. This amine-catalyzed sequence has been extended to the enantioselective construction of furanoindoline frameworks. Application of this pyrroloindoline-forming reaction to natural product synthesis has been accomplished in the context of the enantioselective synthesis of (-)-flustramine B.

| S-EPMC397409 | biostudies-literature

Crystal structure of [K(18-crown-6)]+ 2[Pt(CN)4]2.

Project description:In the title compound, di-μ-cyanato-1:2κ2 N:C;2:3κ2 C:N-di-cyanato-2κ2 C-bis-(1,4,7,10,13,16-hexa-oxa-cyclo-octa-deca-ne)-1κ6 O;3κ6 O-1,3-dipotassium(I)-2-platinum(II), [K2Pt(CN)4(C12H24O6)2] or [K(18-crown-6)]2·[Pt(CN)4], two trans-orientated cyano groups of the square-planar [Pt(CN)4]2- dianion (Pt site symmetry ) bind to one potassium ion each, which are additionally coordinated by the six O atoms of 18-crown-6. No Pt⋯Pt inter-actions occur in the crystal, but very weak Pt⋯H contacts (2.79 Å) are observed.

| S-EPMC6895955 | biostudies-literature

Enantioselective Synthesis of Dioxatriquinane Structural Motifs for HIV-1 Protease Inhibitors Using a Cascade Radical Cyclization.

Project description:Synthesis of novel HIV-1 protease inhibitors incorporating dioxatriquinane-derived P2-ligands is described. The tricyclic ligand alcohol contains five contiguous chiral centers. The ligand alcohols were prepared in optically active form by an enzymatic asymmetrization of mesodiacetate, cascade radical cyclization, and Lewis acid catalyzed reduction as the key steps. Inhibitors with dioxatriquinane-derived P2-ligands exhibited low nanomolar HIV-1 protease activity.

| S-EPMC4500529 | biostudies-literature