122902-06-1Relevant academic research and scientific papers
Enantioselective Conjugate Addition of Stabilized Arylzinc Iodide to Enones: an Improved Protocol of the Hayashi Reaction
Casotti, Gianluca,Rositano, Vincenzo,Iuliano, Anna
, p. 1126 - 1131 (2020/12/17)
Stabilised arylzinc iodide, prepared by direct insertion of zinc into aryl iodides, were used as nucleophiles in the Hayashi Rh-catalysed enantioselective conjugate addition to enones. The reaction conditions were optimized in the addition of phenylzinc i
Synthesis of multinuclear Rh(I) complexes bearing triazolylidenes and their application in C-C and c-Si bond forming reactions
Mendoza-Espinosa, Daniel,Rendón-Nava, David,Vásquez-Pérez, Jose M.,Sandoval-Chávez, Cesar I.,Alvarez-Hernández, Alejandro
supporting information, p. 3961 - 3971 (2020/12/01)
Multidentate carbene ligands are valuable frameworks for the preparation of carbene complexes displaying higher nuclearity. In the present work, we report the synthesis of a series of mono- to tetra-[Rh(COD)I] complexes (3a- d) supported by mesoionic triazol-5-ylidenes. The general synthetic procedure involves the one step reaction of the appropriate triazolium (2a-d) salt in the presence of KHMDS and stoiquiometric amounts of the rhodium(I) precursor. Treatment of complexes 3a-d with an excess of carbon monoxide allows for the quantitative preparation of complexes 4a-d featuring a [Rh(CO)2I] fragment used for the detemination of the donor properties of the new triazolylidene ligands. All complexes have been fully characterized by means of 1H and 13C NMR spectroscopy, melting point, elemental analysis, and in the case of complex 3a, by X-ray crystallography. Comparison of the catalytic activity of the new rhodium complexes in C-C and C-Si bond forming processes demonstrate the enhanced performance of the tetranuclear species suggesting the possibility of strong cooperative effects in these multinuclear complexes.
Palladium-Catalyzed Direct β-C?H Arylation of Ketones with Arylboronic Acids in Water
Hu, Xiaoyun,Yang, Xiaobo,Dai, Xi-Jie,Li, Chao-Jun
supporting information, p. 2402 - 2406 (2017/07/22)
A palladium-catalyzed direct β-C?H arylation of ketones was developed under mild conditions in water, featuring commercially available arylboronic acids as nucleophilic aryl sources and o-iodoxybenzoic acid as the oxidant. The method provides a concise route to access β-arylated ketones. Preliminary studies indicated that direct asymmetric β-C?H arylation of ketones could be achieved by this strategy. (Figure presented.).
Heterogeneous Gold Catalyst: Synthesis, Characterization, and Application in 1,4-Addition of Boronic Acids to Enones
Moragues, Alaina,Neat?, Florentina,Pa?rvulescu, Vasile I.,Marcos, Maria Dolores,Amorós, Pedro,Michelet, Véronique
, p. 5060 - 5067 (2015/09/15)
The new 1 wt % Au/TiO2-UVM-7 catalyst was prepared and fully characterized. This heterogeneous catalyst proved to be active, selective and recyclable for the unprecedented gold-catalyzed 1,4-addition of various functionalized arylboronic acids to 2-cyclohexen-1-one and other selected enones using toluene as a solvent. The gold-based catalyst was recycled two times and played an active role in this reaction, and the nature of the solvent determined a remarkable change in the products' selectivities.
Triazolium salts as appropriate catalytic scaffolds for 1,4-additions to α,β-unsaturated carbonyls
Bratko, Ielyzaveta,Guisado-Barrios, Gregorio,Favier, Isabelle,Mallet-Ladeira, Sonia,Teuma, Emmanuelle,Peris, Eduardo,Gomez, Montserrat
, p. 2160 - 2167 (2014/04/17)
1,2,3-Triazole derivatives containing a rigid dihydroanthracenyl skeleton are suitable precursors for both organometallic and organo-based catalysts. A Rh-carbene complex and the triazolium salt efficiently catalyzed the 1,4-additions of C- and heterodonor reagents to α,β-unsaturated carbonyl substrates, respectively. Copyright
Air-stable solid aryl and heteroaryl organozinc pivalates: Syntheses and applications in organic synthesis
Manolikakes, Sophia M.,Ellwart, Mario,Stathakis, Christos I.,Knochel, Paul
supporting information, p. 12289 - 12297 (2015/03/31)
A wide range of air-stable, solid, polyfunctional aryl and heteroarylzinc pivalates were efficiently prepared by either magnesium insertion or Hal/Mg exchange followed by transmetalation with Zn(OPiv)2 (OPiv=pivalate). By reducing the amount of
Preparation, hydrogen bonds, and catalytic activity in metal-promoted addition of arylboronic acids to enones of a rhodium complex containing an NHC ligand with an alcohol function
Penafiel, Itziar,Pastor, Isidro M.,Yus, Miguel,Esteruelas, Miguel A.,Olivan, Montserrat
, p. 6154 - 6161 (2012/10/29)
The complex RhCl(COD){3-benzyl-1-(2-hydroxy-2-phenylethyl)imidazol-2- ylidene} has been prepared by reaction of the dimer [Rh(μ-OMe)(COD)] 2 with 3-benzyl-1-(2-hydroxy-2-phenylethyl)imidazolium chloride and characterized by X-ray diffraction analysis. The structure reveals that 75% of the molecules are associated through intermolecular O-H...Cl hydrogen bonds between the OH group of the NHC substituent of one molecule and the chloride ligand of the adjacent molecule. This complex catalyzes the addition of arylboronic acids to cyclic and acyclic enones in anhydrous toluene. The alcohol function of the substituent of the NHC ligand plays the role assigned to water in previous cases.
Rhodium-catalyzed conjugate addition of arylindium reagents to α,β-unsaturated carbonyl compounds
Tato, Rubén,Riveiros, Ricardo,Pérez Sestelo, José,Sarandeses, Luis A.
experimental part, p. 1606 - 1611 (2012/03/11)
A novel rhodium-catalyzed conjugate addition of indium reagents to electron deficient olefins is reported. The reaction takes place in THF/MeOH at 110 °C using arylindium dichlorides, a rhodium(I)-binap complex as catalyst, and α,β-unsaturated ketones and
Well-defined [Rh(NHC)(OH)] complexes enabling the conjugate addition of arylboronic acids to α,β-unsaturated ketones
Truscott, Byron J.,Fortman, George C.,Slawin, Alexandra M. Z.,Nolan, Steven P.
experimental part, p. 7038 - 7041 (2011/11/05)
The synthesis and catalytic activity of three well-defined monomeric rhodium(i) hydroxide complexes bearing N-heterocyclic carbene (NHC) ligands are reported. [Rh(cod)(ICy)(OH)] promoted the 1,4-addition of arylboronic acids to cyclic enones, with TONs an
A homogeneous, recyclable polymer support for rh(I)-catalyzed c-c bond formation
Jana, Ranjan,Tunge, Jon A.
experimental part, p. 8376 - 8385 (2011/12/04)
A robust and practical polymer-supported, homogeneous, recyclable biphephos rhodium(I) catalyst has been developed for C-C bond formation reactions. Control of polymer molecular weight allowed tuning of the polymer solubility such that the polymer-supported catalyst is soluble in nonpolar solvents and insoluble in polar solvents. Using the supported rhodium catalysts, addition of aryl and vinylboronic acids to the electrophiles such as enones, aldehydes, N-sulfonyl aldimines, and alkynes occurs smoothly to provide products in high yields. Additions of terminal alkynes to enones and industrially relevant hydroformylation reactions have also been successfully carried out. Studies show that the leaching of Rh from the polymer support is low and catalyst recycle can be achieved by simple precipitation and filtration.
