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1,4-Enynes

FORMATION OF DIENYL COMPLEXES BY REACTION OF OsHCI(CO)(P Pr3)2 WITH ENYNES [Pg.14]

The complex OsHCl(CO)(P Pr3)2 reacts with 2-methyl-l-buten-3-yne to give the dienyl derivative Os ( )-CH=CHC(Me)=CH2 Cl(CO)(P,Pr3)235 in 86%, which is a result of the selective addition of the Os—H bond of the starting complex to the carbon-carbon triple bond of the enyne (Eq. 4). [Pg.14]

An important contribution of the resonance form b requires the donation of electron density form the metal to the dienyl ligand [M(dM) - C(pn-) contribution], The presence of a carbonyl group (a strong TT-acceptor ligand) trans to the dienyl reduces the M(dM) - C(ptt) contribution and, therefore, the nucleo-philicity of the unsaturated ii -carbon ligand. Then the nucleophilic center of the molecule is not the alkenyl ligand but the metallic center, and the protonation at the metal leads to the olefin via reductive elimination from a hydride-dienyl intermediate.24 [Pg.16]

The cis-trans isomerization of alkenyl ligands in transition metal alkenyl compounds is proposed to occur via zwitterionic carbene intermediates.46 According to this, the low contribution of the form b to the metal-dienyl bond in Os (Z)-CH=CHC(Me)=CH2 K1-0C(0)Me (C0)2(P,Pr3)2 could explain why this compound does not evolve into its (if )-isomer. [Pg.16]


Vigreux column gave the enyne alcohol, b.p. 75 C/15 mmHg, n 1.4955, in 55-7451 yield. [Pg.64]

The enyne system in the amines 828=88-8 8-882 can be reversed by potassium amide in liquid ammonia. Addition of the enyne amines to an equivalent amount of this reagent gives the potassium acetylides, K-8e8-88=88-8R2, from which the ynene" amines can be obtained in excellent yields by addition of solid ammonium chloride. [Pg.88]

This isomerization, which must proceed through a 1,2,3-trienylanine, is not "contra-thermodynamic", since with a catalytic amount of potassium tert.-butoxide the same result is obtained. Enyne ethers, H2C=CH-CsC-0R, undergo a similar conversion into HCeC-CH=CH-OR upon interaction with alkali metal amides in liquid NH3, followed by hydrolysis . Enyne sulphides, H2C=CH-CsC-SR, and the hydrocarbons H2C=CH-CsC-R (R = or phenyl) give only tars or polymeric products under... [Pg.89]

A mixture of 1 g of KO-terfc.0.6 g of HO-tert.-CgHg and 40 ml of dry, pure HHPT was warmed at 40-50°C until all of the solid material had disappeared. The solution obtained was cooled to 15°C and 15 g of the enyne ether (note 1) were added in 2 min. The temperature of the mixture was kept at aa. 25°C and after the addition this temperature was maintained for an additional 10 min. [Pg.97]

As indicated in the general scheme below, butatrienes are the first products from base-induced 1,4-elinination of hydrogen and a suitable leaving group. The butatriene in general very readily undergoes isomerization into enynes, if sufficiently "acidic" protons are available (see Chapter 11 in Ref. 3a). In aprotic media cumulenic ethers are fixed as their lithio derivatives if an excess of alkyllithium is applied... [Pg.115]

Other 1,4-eliminations of synthetic interest are the formation of enyne amines 48... [Pg.116]

Treatment of conjugated enyne systems, H C-C=C-CeC-CH-OR, with a suitable base in principle may give rise to 1,6-elimination of HOR with primary formation of the system C=C-C=C=C=C, which subsequently may undergo isomerization to a dienyne. ... [Pg.117]

Jote I. If more CuBr is used, the yields of the enyne are lower and more residue... [Pg.187]

Vote 2. A large excess of R MgCl is required, as the subsequent metallation of the enyne is rapid. In the case of C2H5 the Grignard reagent was prepared from ethyl bromide. [Pg.187]

To a solution of 0.10 mol of the enyne alcohol (see Chapter III, Exp. 41) in 140 ml of dry diethyl ether was added in 15 min with cooling at about -30°C a solution of 0.22 mol of ethyllithium in about 180 ml of diethyl ether (see Chapter II, Exp. 1). The clear solution was then warmed to 25 C and after standing for 10 min at that temperature, it was cautiously poured into 200 ml of an aqueous solution of 30 g of NH,C1. The layers formed after standing were separated, and the aqueous layer was extracted three times with diethyl ether. The combined... [Pg.208]

The alkynyl iodide 150 undergoes the oxidative addition to form an alky-nylpalladium iodide, and subsequent insertion of an alkene gives the conjugated enyne 151 under phase-transfer conditions[120]. [Pg.149]

Terminal alkynes undergo the above-mentioned substitution reaction with aryl and alkenyl groups to form arylalkynes and enynes in the presence of Cul as described in Section 1.1.2.1. In addition, the insertion of terminal alkynes also takes place in the absence of Cul, and the alkenylpalladium complex 362 is formed as an intermediate, which cannot terminate by itself and must undergo further reactions such as alkene insertion or anion capture. These reactions of terminal alkynes are also treated in this section. [Pg.179]

In the alkylative cyclization of the 1,6-enyne 372 with vinyl bromide, formation of both the five-membered ring 373 by exn mode carbopalladation and isomerization of the double bonds and the six-membered ring 374 by endo mode carbopalladation are observed[269]. Their ratio depends on the catalytic species. Also, the cyclization of the 1,6-enyne 375 with /i-bromostyrene (376) affords the endo product 377. The exo mode cyclization is commonly observed in many cases, and there are two possible mechanistic explanations for that observed in these examples. One is direct endo mode carbopalladation. The other is the exo mode carbopalladation to give 378 followed by cyclopropana-tion to form 379, and the subsequent cyclopropylcarbinyl-homoallyl rearrangement affords the six-membered ring 380. Careful determination of the E or Z structure of the double bond in the cyclized product 380 is crucial for the mechanistic discussion. [Pg.180]

The benzene derivative 401 by the intermolecular insertion of acrylate[278], A formal [2 + 2+2] cycloaddition takes place by the reaction of 2-iodonitroben-zene with the 1,6-enyne 402. The neopentylpalladium intermediate 403 undergoes 6-endo-lrig cyclization on to the aromatic ring to give 404[279],... [Pg.183]

The cyclic 2,4-dienoate 184, formed by the Pd-catalyzed cyclization of the 1,6-enyne 183, reacted with 154 to form the azulene derivative 185[118], The 3-methylenepyrrolidine 188 is formed by the reaction of the Zn reagent 186 with the chiral imine 187 with high diastereomeric excess. The structure of the allylic ethers is important for obtaining high diastereoselectivity[l 19],... [Pg.315]

In the coupling of the allenyl ester 7 with a terminal alkyne, an electron-deficient phosphine (Ph3P) gave the enyne-conjugated ester 8 as the major product, while an electron-rich phosphine (TDMPP or TTMPP) yielded the non-conjugated enyne esters ( )- and (Z)-9[4],... [Pg.451]


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1 ,3-Enynes Epoxides

1 ,3-Enynes From carbonyl compounds

1 ,3-Enynes Tetrakis palladium

1,3 enynes/1,3 diynes

1,3 enynes/1,3 diynes hydrogenation

1,3-Enynes special

1,4-Enyne esters, cycloaddition

1,4-Enynes acetylene derivs., synthesi

1,6-enyne

1- Amino-2-mercaptobenzene, reaction with enynes

1- Chloro-1,3-enyne

1.3- Enynes alkynes

1.3- Enynes from alkynes

1.3- Enynes lithium propargyls

1.3- Enynes pyridines

1.3- Enynes stereoselective

1.3- enyne, hydrosilylation

1.4- Enyn-3-ones

1.4- Enynes via boron-ene reaction

1.4- Enynes, allenylzincation

1.5- Enynes Cope rearrangement

1.5- dienes and 1,5-enynes

1.6- Enynes cyclization via intramolecular ene reaction

1.6- Enynes ene reactions

1.6- Enynes palladium catalysis

1.7- Enynes intramolecular

3- Acyloxy 1,4-enynes, cycloaddition

3- Aza-l,5-enynes

A, -Enynes

Acceptor-substituted enyne

Acceptor-substituted enynes

Acceptor-substituted enynes 1.4- addition

Acceptor-substituted enynes 1.4- reduction

Acceptor-substituted enynes NMR spectroscopic investigations

Acceptor-substituted enynes anti-Michael addition

Acceptor-substituted enynes mechanism

Acceptor-substituted enynes tandem 1,6- and 5,6-addition

Acetylene derivatives enynes

Addition to Conjugated Enynes and Related Reactions

Addition to Enynes

Additions to Conjugated Enynes

Aldehyde-enyne substrate

Alkenes cross-metathesis, enyne

Alkenynes s. Enynes

Alkynes enyne constructs

Alkynes enyne derivatives

Alkynes enyne formation

Alkynes enyne, hydrogenation

Alkynes intermolecular enyne cross-metathesis

Alkynes tandem enyne metathesis

Allenyl enyne

Allenylidene enyne metathesis

Allyl chlorides, coupling with enynes

Benzannulation of Enyne with Diyne

Benzannulation of Enynes with Alkynes

Benzannulation, enyne/diyne conjugation

Bicyclization of Enynes

Carbocyclization of diynes and enynes

Carbocyclizations enyne

Carbocyclizations enyne cycloisomerization

Carbolithiation. 1,3-enynes

Carbometallation of conjugated enynes

Cascade Reactions of Enynes

Cascade Reactions of l,n-Enynes

Cascade enyne metathesis

Case Study. Polymerization of 4-Substituted Aromatic Enynes

Cationic gold complexes, enyne

Chiral enyne

Cis-enyne

Cis-enynes

Conjugated enyne

Conjugated enynes

Conjugated enynes synthesis

Cross-metathesis enynes

Cross-metathesis of enyne

Cross-metathesis, transition metal-enyne

Cyanocuprates, reactions with enynes

Cyclization 5- endo enyne

Cyclization of 1,6-Enynes and 1,7-Diynes

Cyclization of enyne

Cyclization of enynes

Cyclizations 1,5-enynes

Cyclizations enyne

Cycloaddition of 3-acyloxy-l,4-enynes

Cycloaddition of enynes

Cyclobutanones from enynes

Cycloisomerization of 1,6-enynes

Cycloisomerizations 1.5- enynes

Cycloisomerizations enynes, palladium®) acetate

Cyclopropanes Enyne

Diaryl-enynes

Diels-Alder reactions enyne metathesis

Diene formations, transition metal-enyne

Dienes from enyne cross metathesis

Diynes cross-benzannulation with enynes

Domino metathesis reactions enyne

Electron-deficient enyne

Enolates enyne

Enolates enyne cyclization

Enolization Enynes

Enynals

Enynals, reactions

Enyne 1,4-diene formation

Enyne Alder-ene reactions

Enyne Cycloisomerization and Related Reactions

Enyne RCM

Enyne acetals

Enyne acetates

Enyne acetates Sn2" substitution

Enyne alcohols

Enyne asymmetric 1,4-diene formation

Enyne carbocyclization

Enyne carbodiimides

Enyne computational study

Enyne couphng

Enyne cross metathesis

Enyne cumulenes

Enyne cyclization

Enyne cycloisomerisation

Enyne cycloisomerization

Enyne cycloisomerization proposed mechanisms

Enyne cycloisomerizations

Enyne cycloisomerizations enynes

Enyne cydization

Enyne enantioselective

Enyne enantioselectivity

Enyne ketenimines

Enyne lactone formation

Enyne mechanism

Enyne metallacyclopentene

Enyne metathesis

Enyne metathesis Mechanism

Enyne metathesis examples

Enyne oxiranes

Enyne oxiranes Sn2" substitution

Enyne sulphones, addition

Enyne synthesis

Enyne with sulfonamides

Enyne with trans-alkenes

Enyne, gold catalysed reaction

Enyne, yttrium-catalyzed

Enyne-allene

Enyne-allene cyclization

Enyne-allenes

Enyne-allenes, cyclization

Enyne-allenes, cyclizations

Enynes 1,1,2-trisubstituted

Enynes 1.4- , dimerization

Enynes Alder-ene reaction

Enynes Pauson-Khand reaction

Enynes acyclic

Enynes acyclic heteroatom-containing

Enynes addition reactions

Enynes alkyne derivatives

Enynes allenes

Enynes and Diynes

Enynes and Polyunsaturated Hydrocarbons

Enynes and propargylation

Enynes as Substrates

Enynes benzannulation

Enynes benzannulation reactions

Enynes bicyclization

Enynes bicyclization-carbonylation

Enynes carbomagnesiation

Enynes cross-benzannulation)

Enynes cyclic

Enynes cyclization

Enynes cycloaddition

Enynes cycloisomerization

Enynes cyclopropanation

Enynes deprotonation

Enynes enyne cyclodimerization

Enynes enyne diyne annulation

Enynes fluorinated

Enynes formation

Enynes free-radical cyclization

Enynes functionalized

Enynes functions

Enynes haloalkyne coupling

Enynes homodimerization

Enynes in vitamin D synthesis

Enynes intramolecular carbopalladation

Enynes intramolecular cyclization

Enynes intramolecular cycloaddition with isocyanides

Enynes ketenes

Enynes macrocyclization

Enynes metathesis

Enynes nitro

Enynes nucleophilic additions

Enynes of carbon nucleophiles

Enynes of nitrogen nucleophiles

Enynes of oxygen nucleophiles

Enynes of phosphorus nucleophiles

Enynes of silicon nucleophiles

Enynes of sulphur nucleophiles

Enynes organic synthesis

Enynes palladium acetate

Enynes preparation

Enynes reaction mechanisms

Enynes reaction with Fischer carbene complexes

Enynes reactivity mechanism

Enynes semihydrogenation

Enynes skeletal reorganization

Enynes skipped

Enynes stereospecific synthesis

Enynes tetrasubstituted

Enynes thiocarbonylation

Enynes titanium complex

Enynes transformations

Enynes via Sakurai-Hosomi allylsilane conjugate addition

Enynes via hydroalumination

Enynes zirconium-promoted

Enynes, 1-chlorostereospecific synthesis

Enynes, Negishi cross-coupling reaction

Enynes, carboalumination

Enynes, carbonylation

Enynes, carbonylation reaction

Enynes, conjugated cross-benzannulation with diynes

Enynes, conjugated homodimerization

Enynes, hydroboration-oxidation

Enynes, hydrosilation

Enynes, hydrozirconation

Enynes, intramolecular metathesis

Enynes, reduction

Enynes, synthesis

Enynes/dienynes

Enynes/dienynes Diels—Alder reactions

Enynes/dienynes alkynes

Enynes/dienynes cycloaddition

Enynes/dienynes reactions

Enynes/dienynes substitution

Epoxidation conjugated enyne

Epoxy enynes

Ethylene derivatives enynes

Examples of Enyne Metathesis

Gilman cuprates, reactions with enynes

Gold -catalyzed enyne cyclization

Gold catalysis 1,5-enyne

Gold enyne cyclizations

Grignard reagents with enynes

Grubbs catalyst enyne metathesis

Hetero-enyne metathesis

Hydroboration enynes

Hydroboration of Enynes and Diynes

Hydrosilylation enynes

Hydrosilylation of enynes

Intermolecular with 1,3-enyne

Intramolecular Coupling of Enynes or Alkynes

Isomerization enyne cycloisomerization

James M. Takacs 2 Palladium-Catalyzed Benzannulation Reactions of Conj ugated Enynes and Diynes

Kinetic isotope effects enyne-allene cyclization

L,n-enynes

Macrocyclization using enyne metathesis

Macrocyclization, enyne

Metal-catalyzed enyne reactions

Metathesis chemistry enynes

Metathesis group-selective enyne

Metathesis of enyne

Metathesis reactions of enynes and dienynes

Metathesis ring-closing enyne

Metathesis ruthenium-catalyzed enyne

Metathesis transition metal-enyne structure

Natural products synthesis enyne cycloisomerization

Nucleophilic Addition to Alkynes and Conjugated Enynes

Nucleophilic addition reactions of enynes, acceptor-substituted

Of 1,5-enynes

Of enyne

Olefins enyne ring closing metathesis

Olefins enynes

Organocopper compounds, reactions with enynes

Organolithium compounds, reactions with enynes

Organosilver Species as Intermediates in Catalyzed Enyne or Arylyne Synthesis

Ozonolysis of enyne

Palladium enyne synthesis

Palladium enynes

Palladium-catalyzed 1,6-enyne

Palladium-catalyzed 1,6-enyne cycloisomerizations

Palladium-catalyzed cycloisomerization of enyne

Palladium-catalyzed enyne cyclizations

Palladium-catalyzed enyne cycloisomerization

Pauson-Khand reaction bicyclization-carbonylation of enynes

Practical Aspects of Syntheses Based on Enyne-Allenes

Preparation of Enynes by Elimination

Propyne, 1,3-bis anion enynes from

Propyne, l,3-bis dilithium anion 1,3-enynes from

Reactions of Conjugated Enynes

Reactions of Enynes

Reactions of Enynes with Alkynes

Rearrangement reactions enynes

Reductive Cyclization of 1,6-Diynes and 1,6-Enynes

Reductive cyclization of enyne

Ring closing metathesis enyne precursors

Ring systems enyne cycloisomerization

Ring-closing enyne

Ring-closing metathesis enynes

Ring-closing metathesis reaction enyne

Ring-opening metathesis enynes

Ruthenium(arene) Catalyst in Diene and Enyne RCM

Ruthenium-Catalyzed Hydrative Cyclization of 1,5-Enynes

Selective Preparation of Conjugated Enynes

Silylative Cyclocarbonylation of 1,6-Diynes and 1,6-Enynes

Skeletal rearrangements enynes

Stannylated enynes

Stereoselective Routes to Conjugated Enynes

Suzuki enynes, stereodefined

Synthesis of Conjugated Enynes

Synthesis of Enynes

Tandem enyne metathesis

Thiols enyne derivatives

Titanium catalysts enynes

Transition enyne ring-closing metathesis

Transition metals metal enyne structures

Zhang enyne cycloisomerization

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