14371-19-8Relevant articles and documents
Variation on the π-Acceptor Ligand within a RhI?N-Heterocyclic Carbene Framework: Divergent Catalytic Outcomes for Phenylacetylene-Methanol Transformations
Galiana-Cameo, María,Passarelli, Vincenzo,Pérez-Torrente, Jesús J.,Di Giuseppe, Andrea,Castarlenas, Ricardo
, p. 2947 - 2957 (2021/07/16)
A series of neutral and cationic rhodium complexes bearing IPr {IPr=1,3-bis-(2,6-diisopropylphenyl)imidazolin-2-carbene} and π-acceptor ligands are reported. Cationic species [Rh(η4-cod)(IPr)(NCCH3)]+ and [Rh(CO)(IPr)(L)2]+ (L=pyridine, CH3CN) were obtained by chlorido abstraction in suitable complexes, whereas the cod-CO derivative [Rh(η4-cod)(IPr)(CO)]+ was formed by the carbonylation of [Rh(η4-cod)(IPr)(NCCH3)]+. Alternatively, neutral derivatives of type RhCl(IPr)(L)2 {L=tBuNC or P(OMe)3} can be accessed from [Rh(μ-Cl)(η2-coe)(IPr)]2. In addition, the mononuclear species Rh(CN)(η4-cod)(IPr) was prepared by cyanide-chlorido anion exchange, which after carbonylation afforded the unusual trinuclear compound [Rh{1κC,2κN-(CN)}(CO)(IPr)]3. Divergent catalytic outcomes in the phenylacetylene-methanol transformations have been observed. Thus, enol ethers, arisen from hydroalkoxylation of the alkyne, were obtained with neutral Rh?CO catalyst precursors whereas dienol ethers were formed with cationic catalysts. Variable amounts of alkyne dimerization, cyclotrimerization or polymerization products were obtained in the absence of a strong π-acceptor ligand on the catalyst.
Base-promoted stereoselective hydroalkoxylation of alkynes
Patel, Monika,Sushmita,Verma, Akhilesh Kumar
, p. 169 - 175 (2018/09/14)
Base-promoted and stereoselective synthesis of C(sp2)-O bond through the anti-Markovnikov addition of alcohols onto alkyne and has been discovered. Developed protocol tolerates a wide variety of functional groups to afford styryl ethers from commercially
Intermolecular Hydroalkoxylation of Terminal Alkynes Catalyzed by a Dipyrrinato Rhodium(I) Complex with Unusual Selectivity
Lam, Raphael H.,Walker, D. Barney,Tucker, Matthew H.,Gatus, Mark R. D.,Bhadbhade, Mohan,Messerle, Barbara A.
supporting information, p. 4312 - 4317 (2015/09/22)
An operationally simple and atom-economical method for the E-selective preparation of enol ethers is described. A novel dicarbonyl(5-phenyldipyrrinato)rhodium complex, 2, was prepared in four synthetic steps, characterized by X-ray crystallography and NMR
Z-selective, anti-Markovnikov addition of alkoxides to terminal alkynes: An electron transfer pathway?
Cuthbertson, James,Wilden, Jonathan D.
, p. 4385 - 4392 (2015/06/08)
Potassium alkoxides undergo anti-Markovnikov addition to aryl-substituted alkynes with Z selectivity in DMF as the solvent. The yields and efficiency of the reaction was also found to be enhanced by the addition of a secondary amine ligand such as N,N′-di
Transition metal-free stereoselective α-vinylation of cyclic ketones with arylacetylenes in the superbasic catalytic triad potassium hydroxide/tert-butyl alcohol/dimethyl sulfoxide
Trofimov, Boris A.,Schmidt, Elena Yu.,Zorina, Nadezhda V.,Ivanova, Elena V.,Ushakov, Igor A.,Mikhaleva, Al'Bina I.
supporting information; experimental part, p. 1813 - 1818 (2012/08/13)
A stereoselective α-vinylation of cycloaliphatic ketones with arylacetylenes under the transition metal-free conditions has been developed. The reaction is promoted by the superbasic catalytic triad potassium hydroxide/tert-butyl alcohol/dimethyl sulfoxide (80-110 °C, 1-2 h) to afford mainly (E)-β,γ-ethylenic ketones, their (E)-α,β-isomers being minor products, in up to 83% total yield. Copyright
Rhodium-catalyzed anti-Markovnikov intermolecular hydroalkoxylation of terminal acetylenes
Kondo, Masataka,Kochi, Takuya,Kakiuchi, Fumitoshi
supporting information; experimental part, p. 32 - 34 (2011/03/16)
We report here the first transition-metal-catalyzed anti-Markovnikov intermolecular hydroalkoxylation of terminal acetylenes to give enol ethers in high yields without using bases. Arylacetylenes as well as alkenyl- and alkylacetylenes were coupled with aliphatic alcohols, and the products were obtained with high Z selectivity in most cases. Effective catalysts were 8-quinolinolato rhodium complexes, which are structurally simple but have been relatively unexplored as catalysts.
Solvolysis of styryliodonium salt: Products, rates, and mechanisms
Okuyama, Tadashi,Ishida, Yoshimi,Ochiai, Masahito
, p. 163 - 170 (2007/10/03)
The solvolysis of phenyl[(E)-styryl]iodonium tetrafluoroborate in various solvents was examined at 50-70°C by means of product and kinetic studies with the normal and labeled substrates. The reactions involved are α-elimination and substitutions with configurational retention and inversion. In methanol and ethanol, the main reaction is α-elimination, along with about 5% of substitution with the ratio of inversion/retention from 4/6 to 3/7. As the basicity of the solvent decreases, the reaction rate and the fraction of α-elimination decrease, and at the same time the ratio of inversion/retention of substitution also decreases. In 2,2,2- trifluoroethanol, only the substitution with retention was observed. Labeling experiments showed that complete isotope scrambling occurred between the olefinic hydrogens of the retained product while the deuterium remained at the original position of the inverted product. The substitution mechanism is concluded to involve parallel pathways: an S(N) 1-type with a vinylenebenzenium ion intermediate leading to retention and a vinylic S(N) 2- type with a direct attack by the nucleophilic solvent leading to inversion.
Cesium hydroxide catalyzed addition of alcohols and amine derivatives to alkynes and styrene
Tzalis, Dimitrios,Koradin, Christopher,Knochel, Paul
, p. 6193 - 6195 (2007/10/03)
In the presence of catalytic amounts of cesium hydroxide (CsOH · H2O), alcohols, substituted anilines and heterocyclic amines undergo an addition in NMP to phenylacetylene leading to functionalized enol ethers and enamines. Anilines add to styrene (90-120°C, 12-14 h) leading to N-substituted anilines in satisfactory yields.
NUCLEOPHILIC ADDITION TO ALKYNES IN SUPERBASIC CATALYTIC SYSTEMS. IV. VINYLATION OF ALCOHOLS BY PHENYLACETYLENE. A PATH TO PHENYLACETALDEHYDE AND ITS ACETALS
Tarasova, O. A.,Mikhailova, A. I.,Shmidt, E. Yu.,Polovnikova, R. I.,Trofimov, B. A.
, p. 860 - 862 (2007/10/02)
A method is proposed for the synthesis of phenylacetaldehyde, involving nucleophilic addition of methanol to phenylacetylene in the potassium hydroxide-DMSO system followed by acid-catalyzed hydrolysis of the obtained methyl styryl ether.Electrophilic addition of alcohols and glycerol to the latter in the presence of p-toluenesulfonic acid leads to high yields of the corresponding acetals of phenylacetaldehyde.
COMPETITION BETWEEN VINYLIC SUBSTITUTION AND CONJUGATE ADDITION IN THE REACTIONS OF VINYL SELENOXIDES AND VINYL SELENONES WITH NUCLEOPHILES IN DMF
Tiecco, Marcello,Chianelli, Donatella,Testaferri, Lorenzo,Tingoli, Marco,Bartoli, Donatella
, p. 4889 - 4896 (2007/10/02)
Vinyl selenoxides and vinyl selenones present a different reactivity towards thiolate or alkoxide anions in DMF.In the case of selenoxides the addition of the nucleophiles regioselectively occurs at the α-carbon leading to the formation of the vinylic sub
