Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

An annulation reaction for the synthesis of cross-conjugated triene-containing hydroindanes from acyclic precursors.

ABSTRACT: In efforts directed toward the synthesis of seco-prezizaane sesquiterpenoids, a stereoselective annulation reaction has been developed between 4-hydroxy-1,6-enynes and TMS-alkynes that delivers cross-conjugated triene-containing hydroindanes. Contrary to previous reports, enyne substrates bearing two propargylic ethers enable the presumed organometallic intermediate to be trapped by double elimination. The tendency of products from this annulation to undergo Diels-Alder-based dimerization was harnessed to accomplish a two-step complexity-generating sequence en route to densely functionalized carbo- and heteorocyclic systems.

SUBMITTER: Cheng X

PROVIDER: S-EPMC4184447 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

An annulation reaction for the synthesis of cross-conjugated triene-containing hydroindanes from acyclic precursors.

Cheng Xiayun X Micalizio Glenn C GC

Organic letters 20140912 19

In efforts directed toward the synthesis of seco-prezizaane sesquiterpenoids, a stereoselective annulation reaction has been developed between 4-hydroxy-1,6-enynes and TMS-alkynes that delivers cross-conjugated triene-containing hydroindanes. Contrary to previous reports, enyne substrates bearing two propargylic ethers enable the presumed organometallic intermediate to be trapped by double elimination. The tendency of products from this annulation to undergo Diels-Alder-based dimerization was ha ...[more]

PMID: 25216381

Similar Datasets

Ferrocene-Containing Conjugated Oligomers Synthesized by Acyclic Diene Metathesis Polymerization.

Project description:A series of conjugated, symmetrical, and ferrocene-containing main-chain monomers was prepared following a gentle coupling reaction. Ferrocene-containing oligomers with all-trans-configured vinylene bonds could be synthesized via acyclic diene metathesis (ADMET) polymerization. These oligomers had a larger Stokes shift (2400 to 2600 cm-1) and both exhibited stable and reversible electrochemistry. Meanwhile, the copolymerization of 1,1'-bis[1-methyl-2-(4-vinylphenyl)ethenyl]ferrocene with 2,7-divinyl-9,9-dioctylfluorene was achieved. The structurally regular copolymers proved their optical and electrochemical properties. The fluorescence intensity of the copolymer gradually enhanced with the increasing number of fluorene units. At the same time, it was also found that the color of the copolymers had a significant change from yellow-green to red.

| S-EPMC6722986 | biostudies-literature

Polar reactions of acyclic conjugated bisallenes.

Project description:The chemical behaviour of various alkyl-substituted, acyclic conjugated bisallenes in reactions involving polar intermediates and/or transition states has been investigated on a broad scale for the first time. The reactions studied include lithiation, reaction of the thus formed organolithium salts with various electrophiles (among others, allyl bromide, DMF and acetone), oxidation to cyclopentenones and epoxides, hydrohalogenation (HCl, HBr addition), halogenation (Br(2) and I(2) addition), and [2 + 2] cycloaddition with chlorosulfonyl isocyanate. The resulting adducts were fully characterized by spectroscopic and analytical methods; they constitute interesting substrates for further organic transformations.

| S-EPMC3566852 | biostudies-other

Development of a Cross-Conjugated Vinylogous [4+2] Anionic Annulation and Application to the Total Synthesis of Natural Antibiotic (±)-ABX.

Project description:The cross-conjugated vinylogous [4+2] anionic annulation has been newly developed, the cascade process of which has a high preference for regiochemical control and chemoselectivity, giving rise to exclusively Michael-type adducts in moderate to high yields (up to 94?%, 35 examples). By making use of this approach as a key operation, the first total synthesis of natural antibiotic ABX, in racemic form, has been successfully achieved in a concise 7-step sequence with an overall yield of about 20?%.

| S-EPMC7187479 | biostudies-literature

Synthesis of angularly substituted trans-fused hydroindanes by convergent coupling of acyclic precursors.

Project description:Angularly substituted trans-fused hydroindanes are now accessible by the direct and convergent union of trimethylsilyl (TMS)-alkynes with 4-hydroxy-1,6-enynes by a process that forges three C-C bonds, one C-H bond, and two new stereocenters. The annulation is proposed to proceed by initial formation of a Ti-alkyne complex (with a TMS-alkyne) followed by regioselective alkoxide-directed coupling with the enyne, stereoselective intramolecular cycloaddition, elimination of phenoxide, 1,3-metallotropic shift, and stereoselective protonation of the penultimate allylic organometallic intermediate. Several examples are given to demonstrate the compatibility of this reaction with substrates bearing aromatic and aliphatic substituents, and an empirical model is presented to accompany the stereochemical observations.

| S-EPMC4063191 | biostudies-literature

Synthesis, Chemosensory Properties, and Self-Assembly of Terpyridine-Containing Conjugated Polycarbazole through RAFT Polymerization and Heck Coupling Reaction.

Project description:We report the responsive fluorescence chemosensory phenomena of a carbazole-functionalized crosslinked polymer (PCaT) with pendent terpyridine (tpy) groups as receptors of metal ions. The polymer was synthesized using Heck polymerization between 3,6-dibromide groups in a carbazole-based polymer (PC2Br) and divinyl tpy monomer. The effects of the polymeric structure on the optical and chemosensory properties of the PCaT were compared with those of a carbazole-tpy alternating conjugated polymer (PCT). Photoluminescence titrations demonstrated that the PCaT and PCT had the high sensing ability toward Fe3+ ions, with Stern⁻Volmer constants of 8.10 × 10⁴ and 6.68 × 10⁴ M-1, respectively. The limit of detection (LOD) toward Fe3+ of the PCaT and PCT was estimated to be 1.31 × 10-6 and 1.81 × 10-6 M, respectively, and the superior LOD of the PCaT was ascribed to its lowly crosslinked structure. The fluorescence of the solutions of these polymers that were quenched by Fe3+ ions recovered when trace CN- anions were added because of the high stability constant of the CN-⁻Fe3+ complex. Micellar aggregates with a mean diameter of approximately 239.5 nm were formed by dissolving the PCaT in tetrahydrofuran (THF) solution. Our results suggest that the PCaT is a promising material for chemosensory applications.

| S-EPMC6418694 | biostudies-literature

Nickel-Catalyzed Oxidative Decarboxylative Annulation for the Synthesis of Heterocycle-Containing Phenanthridinones.

Project description:A nickel-catalyzed oxidative decarboxylative annulation reaction of simple benzamides and (hetero)aromatic carboxylates has been developed. This reaction provides access to a large array of phenanthridinones and their heterocyclic analogues, highlighting the utility and versatility of oxidative decarboxylative coupling strategies for C-C bond formation.

| S-EPMC6739634 | biostudies-literature

Surface-Assisted Synthesis of N-Containing π-Conjugated Polymers.

Project description:On-surface synthesis has recently emerged as a powerful strategy to design conjugated polymers previously precluded in conventional solution chemistry. Here, an N-containing pentacene-based precursor (tetraazapentacene) is ex-professo synthesized endowed with terminal dibromomethylene (:CBr2 ) groups to steer homocoupling via dehalogenation on metallic supports. Combined scanning probe microscopy investigations complemented by theoretical calculations reveal how the substrate selection drives different reaction mechanisms. On Ag(111) the dissociation of bromine atoms at room temperature triggers the homocoupling of tetraazapentacene units together with the binding of silver adatoms to the nitrogen atoms of the monomers giving rise to a N-containing conjugated coordination polymer (P1). Subsequently, P1 undergoes ladderization at 200 °C, affording a pyrrolopyrrole-bridged conjugated polymer (P2). On Au(111) the formation of the intermediate polymer P1 is not observed and, instead, after annealing at 100 °C, the conjugated ladder polymer P2 is obtained, revealing the crucial role of metal adatoms on Ag(111) as compared to Au(111). Finally, on Ag(100) the loss of :CBr2 groups affords the formation of tetraazapentacene monomers, which coexist with polymer P1. Our results contribute to introduce protocols for the synthesis of N-containing conjugated polymers, illustrating the selective role of the metallic support in the underlying reaction mechanisms.

| S-EPMC9259725 | biostudies-literature

Synthesis of Gold(III) Complexes with Bidentate Amino-Thiolate Ligands as Precursors of Novel Bifunctional Acyclic Diaminocarbenes.

Project description:Two neutral bis(pentafluorophenyl)thiolate gold(III) complexes with the unsymmetrical S^N ligands 2-aminothiophenol or cysteamine have been synthesized and their reactivity has been studied. Homo- and heterodinuclear compounds were obtained by their coordination to gold(I) or silver(I) derivatives through the sulfur atom. Interestingly, a tetranuclear derivative bearing short gold(I)···gold(I) and the more unusual gold(I)···gold(III) interactions has been prepared. These amino-thiolate derivatives can be used as precursors for the synthesis of novel gold(III) acyclic diaminocarbene complexes by reaction with isocyanides CNR. The nucleophilic attack of the amino group to isocyanide molecules affords the synthesis of unprecedented bidentate C^S acyclic diaminocarbene ligands. All of the complexes are air- and moisture-stable at room temperature and have been spectroscopically and structurally characterized.

| S-EPMC6645091 | biostudies-literature

A Diverted Aerobic Heck Reaction Enables Selective 1,3-Diene and 1,3,5-Triene Synthesis through C-C Bond Scission.

Project description:Substituted 1,3-dienes are valuable synthetic intermediates used in myriad catalytic transformations, yet modern catalytic methods for their preparation in a highly modular fashion using simple precursors are relatively few. We report here an aerobic boron Heck reaction with cyclobutene that forms exclusively linear 1-aryl-1,3-dienes using (hetero)arylboronic acids, or 1,3,5-trienes using alkenylboronic acids, rather than typical Heck products (i.e., substituted cyclobutenes). Experimental and computational mechanistic data support a pericyclic mechanism for C-C bond cleavage that enables the cycloalkene to circumvent established limitations associated with diene reagents in Heck-type reactions.

| S-EPMC6424333 | biostudies-literature

Synthesis of Conjugated Polymers Containing cis-Phenylenevinylenes by Titanium Mediated Reductions.

Project description:The utility of Sato's titanium-mediated reduction of alkynes towards the synthesis of all cis-poly(phenylenevinylene)s (PPVs) is demonstrated by the syn-selective reduction of a variety of model diynes as well as a tetrayne. This technique was then applied to the reduction of a poly(phenyleneethynylene) (PPE) to provide the corresponding all-cis PPV polymer.

| S-EPMC2934907 | 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