Browse
Submit Data
Databases
API
Help

Dataset Information

35 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Stereoselective Synthesis of Homofarnesenes: Establishment of an Efficient Method for the Stereoselective Preparation of Acyclic Tetrasubstituted Olefins.

ABSTRACT: A new method for the stereoselective synthesis of tetrasubstituted olefins is described. ?-Ketophosphonates are alkylated via conventional methods, and a Grignard reagent is used to diastereoselectively add to the carbonyl group of the resulting intermediates. The elimination of hydroxyl phosphonates yielded the desired tetrasubstituted olefins in a stereoselective manner. Thus, homofarnesenes of fire ant trail pheromones have been synthesized efficiently using this strategy.

SUBMITTER: Yin W

PROVIDER: S-EPMC6641643 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Stereoselective Synthesis of Homofarnesenes: Establishment of an Efficient Method for the Stereoselective Preparation of Acyclic Tetrasubstituted Olefins.

Yin Wenhao W Liang Weihong W Guo Liping L Lei Jiaheng J Qiu Fayang G FG

ACS omega 20180426 4

A new method for the stereoselective synthesis of tetrasubstituted olefins is described. β-Ketophosphonates are alkylated via conventional methods, and a Grignard reagent is used to diastereoselectively add to the carbonyl group of the resulting intermediates. The elimination of hydroxyl phosphonates yielded the desired tetrasubstituted olefins in a stereoselective manner. Thus, homofarnesenes of fire ant trail pheromones have been synthesized efficiently using this strategy. ...[more]

PMID: 31458678

Similar Datasets

Highly Stereoselective Synthesis of Tetrasubstituted Acyclic All-Carbon Olefins via Enol Tosylation and Suzuki-Miyaura Coupling.

Project description:A highly stereocontrolled synthesis of tetrasubstituted acyclic all-carbon olefins has been developed via a stereoselective enolization and tosylate formation, followed by a palladium-catalyzed Suzuki-Miyaura cross-coupling of the tosylates and pinacol boronic esters in the presence of a Pd(OAc)2/RuPhos catalytic system. Both the enol tosylation and Suzuki-Miyaura coupling reactions tolerate an array of electronically and sterically diverse substituents and generate high yield and stereoselectivity of the olefin products. Judicious choice of substrate and coupling partner provides access to either the E- or Z-olefin with excellent yield and stereochemical fidelity. Olefin isomerization was observed during the Suzuki-Miyaura coupling. However, under the optimized cross-coupling reaction conditions, the isomerization was suppressed to <5% in most cases. Mechanistic probes indicate that the olefin isomerization occurs via an intermediate, possibly a zwitterionic palladium carbenoid species.

| S-EPMC6059653 | biostudies-literature

Asymmetric Hydrogenation of Unfunctionalized Tetrasubstituted Acyclic Olefins.

Project description:Asymmetric hydrogenation has evolved as one of the most powerful tools to construct stereocenters. However, the asymmetric hydrogenation of unfunctionalized tetrasubstituted acyclic olefins remains the pinnacle of asymmetric synthesis and an unsolved challenge. We report herein the discovery of an iridium catalyst for the first, generally applicable, highly enantio- and diastereoselective hydrogenation of such olefins and the mechanistic insights of the reaction. The power of this chemistry is demonstrated by the successful hydrogenation of a wide variety of electronically and sterically diverse olefins in excellent yield and high enantio- and diastereoselectivity.

| S-EPMC7141762 | biostudies-literature

Stereoselective Synthesis of Tri- and Tetrasubstituted Olefins via 1,6-Additions of Diazo Compounds and Their Precursors to p-Quinone Methides

Project description:Reactions of para-quinone methides (p-QMs) with α-diazo-β-ketosulfones

| S-EPMC9954373 | biostudies-literature

Tetrasubstituted olefins through the stereoselective catalytic intermolecular conjugate addition of simple alkenes to α,β-unsaturated carbonyl compounds.

Project description: Not available

| S-EPMC3869203 | biostudies-literature

Total Synthesis of (-)-Mitrephorone A Enabled by Stereoselective Nitrile Oxide Cycloaddition and Tetrasubstituted Olefin Synthesis.

Project description:A highly enantioselective and diastereoselective total synthesis of the diterpenoid (-)-mitrephorone A is presented. Key to the synthesis are stereocontrolled 1,4-semihydrogenation of a 1,3-diene to a tetrasubstituted double bond, enzyme-catalyzed malonate desymmetrization, and highly diastereoselective nitrile oxide cycloaddition. The streamlined strategy is a considerable improvement to those reported earlier in terms of diastereo- and enantioselectivity. For the first time, the combination of modern Pd-cross-coupling with Cr-catalyzed reduction allows for rapid access to tetrasubstituted olefins with full stereocontrol.

| S-EPMC7564100 | biostudies-literature

Preparation of tetrasubstituted olefins using mono or double aerobic direct C-H functionalization strategies: importance of steric effects.

Project description:A novel protocol for the synthesis of tetrasubstituted olefins through a biomimetic approach has been explored. Both mono- and diarylations were performed under ambient oxygen pressure, giving a range of highly hindered tetrasubstituted alkenes. For diarylation of disubstituted substrates, it was demonstrated that the second arylation is the rate-limiting step of the overall transformation.

| S-EPMC4354172 | biostudies-literature

Efficient Synthesis of α-Branched Purine-Based Acyclic Nucleosides: Scopes and Limitations of the Method.

Project description:An efficient route to acylated acyclic nucleosides containing a branched hemiaminal ether moiety is reported via three-component alkylation of N-heterocycle (purine nucleobase) with acetal (cyclic or acyclic, variously branched) and anhydride (preferentially acetic anhydride). The procedure employs cheap and easily available acetals, acetic anhydride, and trimethylsilyl trifluoromethanesulfonate (TMSOTf). The multi-component reaction is carried out in acetonitrile at room temperature for 15 min and provides moderate to high yields (up to 88%) of diverse acyclonucleosides branched at the aliphatic side chain. The procedure exhibits a broad substrate scope of N-heterocycles and acetals, and, in the case of purine derivatives, also excellent regioselectivity, giving almost exclusively N-9 isomers.

| S-EPMC7571146 | biostudies-literature

Modular and regioselective synthesis of all-carbon tetrasubstituted olefins enabled by an alkenyl Catellani reaction.

Project description:All-carbon tetrasubstituted olefins have been found in numerous biologically important compounds and organic materials. However, regio- and stereocontrolled construction of this structural motif still constitutes a significant synthetic challenge. Here, we show that a modular and regioselective synthesis of all-carbon tetrasubstituted olefins can be realized via alkenyl halide- or triflate-mediated palladium/norbornene catalysis, which is enabled by a modified norbornene containing a C2 amide moiety. This new norbornene co-catalyst effectively suppressed undesired cyclopropanation pathways, which have previously been a main obstacle for developing such reactions. Diverse cyclic and acyclic alkenyl bromides or triflates with a wide range of functional groups can be employed as substrates. Various substituents can be introduced at the alkene C1 and C2 positions regioselectively simply by changing the coupling partners. Initial mechanistic studies provide insights on the rate-limiting step as well as the structure of the actual active ligand in this system.

| S-EPMC7098644 | biostudies-literature

Modular and stereoselective synthesis of tetrasubstituted vinyl sulfides leading to a library of AIEgens.

Project description:Tetraarylethylenes exhibit intriguing photophysical properties and sulfur atom frequently play a vital role in organic photoelectric materials and biologically active compounds. Tetrasubstituted vinyl sulfides, which include both sulfur atom and tetrasubstituted alkenes motifs, might be a suitable skeleton for the discovery of the new material molecules and drug with unique functions and properties. However, how to modular synthesis these kinds of compounds is still challenging. Herein, a chemo- and stereo-selective Rh(II)-catalyzed [1,4]-acyl rearrangements of α-diazo carbonyl compounds and thioesters has been developed, providing a modular strategy to a library of 63 tetrasubstituted vinyl sulfides. In this transformation, the yield is up to 95% and the turnover number is up to 3650. The mechanism of this reaction is investigated by combining experiments and density functional theory calculation. Moreover, the "aggregation-induced emission" effect of tetrasubstituted vinyl sulfides were also investigated, which might useful in functional material, biological imaging and chemicalnsing via structural modification.

| S-EPMC8674301 | biostudies-literature

Stereoselective Synthesis of Exocyclic Tetrasubstituted Vinyl Halides via Ru-Catalyzed Halotropic Cycloisomerization of 1,6-Haloenynes.

Project description:Herein, a ruthenium-catalyzed cycloisomerization that transforms 1,6-haloenynes into 5-membered carbo- and heterocycles that bear exocyclic, stereodefined, tetrasubstituted vinyl halides is reported. The reaction is insensitive to air and water, tolerates a variety of functional groups, and proceeds with good to excellent stereoselectivity and yield.

| S-EPMC5726863 | 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