39255-30-6Relevant academic research and scientific papers
Palladium-Catalyzed Carbonylation of sec- and tert-Alcohols
Dong, Kaiwu,Sang, Rui,Liu, Jie,Razzaq, Rauf,Franke, Robert,Jackstell, Ralf,Beller, Matthias
supporting information, p. 6203 - 6207 (2017/05/22)
A general palladium-catalyzed synthesis of linear esters directly from sec- and tert-alcohols is described. Compared to the classic Koch–Haaf reaction, which leads to branched products, this new transformation gives the corresponding linear esters in high yields and selectivity. Key for this protocol is the use of an advanced palladium catalyst system with L2 (pytbpx) as the ligand. A variety of aliphatic and benzylic alcohols can be directly used and the catalyst efficiency for the benchmark reaction is outstanding (turnover number up to 89 000).
A mild route to solid-supported rhodium nanoparticle catalysts and their application to the selective hydrogenation reaction of substituted arenes
Moreno-Marrodan, Carmen,Liguori, Francesca,Mercadé, Elisabet,Godard, Cyril,Claver, Carmen,Barbaro, Pierluigi
, p. 3762 - 3772 (2015/07/01)
A clean route is described for the preparation of 1.3% (w/w) supported rhodium nanoparticle (3.0 ± 0.7 nm) catalysts onto commercial ion-exchange resins. Their application to the liquid-phase hydrogenation reaction of C=C bonds shows the most active species are obtained under catalytic conditions at room temperature and 1 bar H2. The heterogeneous catalyst shows excellent activity, selectivity and reusability in the hydrogenation reaction of alkenes and substituted arenes under very undemanding conditions. The results are discussed in terms of support effect on the catalytic efficiency.
Hexafluoroisopropanol: A powerful solvent for the hydrogenation of functionalized aromatic compounds
Fache, Fabienne,Piva, Olivier
, p. 1294 - 1296 (2007/10/03)
Various substituted aromatic compounds have been reduced under H 2 using RuCl3. The fluorous solvent hexafluoroisopropanol turned out to be particularly efficient in the case of compounds difficult to reduce in organic solvents.
A catalytic stereo- and chemo-selective method for the reduction of substituted aromatics
Fache,Lehuede,Lemaire
, p. 885 - 888 (2007/10/02)
Various substituted aromatics have been reduced using colloidal ruthenium under H2 pressure with good stereoselectivity (cis/trans up to 60). Interesting chemoselectivities are also observed.
Enzymes in organic synthesis 49. Resolutions of racemic monocyclic esters with pig liver esterase
Toone,Jones
, p. 207 - 222 (2007/10/02)
Pig liver esterase (PLE)- catalyzed hydrolyses of the racemic methyl esters of cyclobutane-, cyclohexane-, and cyclohex-4-ene-carboxylic acids bearing cis-2-methyl or cis-2-bromomethyl substituents are highly stereoselective, giving the corresponding acid products of ≥ 97% ee. The stereoselectivity of the enzyme exhibits the expected reversal for such compounds, with the absolute configurations of the cyclobutane and cyclohexame acids being of the opposite absolute configuration type, and cyclopentane substrates such as cis-1-carbomethoxy-2-methylcyclopentane representing the change-over structures and giving products of only 22%ee. This stereoselectivtiy reversal, and the absolute configurations preferred, are as predicted by the recently proposed active site model for the enzyme.
Stereochemistry of Alkylation of Carboxylic Acid Salt and Ester α Anions Derived from Cyclic Systems.
Krapcho, A.Paul,Dundulis, Edward A.
, p. 3236 - 3245 (2007/10/02)
A stereochemical study of the alkylation of α-lithiated carboxylate salts and esters has been performed.The α anions derived from the bicyclic acids exo-1, endo-1, and 7 (R=H) and the esters 4 and 7 (R=CH3) yield predominantly exo alkylation.As an example, the α anion derived from ester 7 (R=CH3) on treatment with CH3I yields exo-8 (R=R'=CH3) and endo-9 (R=R'=CH3) in a 97:3 ratio, a highly stereoselective reaction.Addition of TMEDA to the reactions involving the α anions derived from exo- or endo-1 did not change the stereochemical alkylation results.The α anions derived from the substituted cyclohexanecarboxylic acids 10, 13, 16, 19, or 22 (where R=H in each case) on methylation yield more axial methylation (axial/equatorial ratios of 0.4-2.7) than the α anions derived from the methyl esters corresponding to these acids.The α anions from the esters yield predominantly equatorial methylated products (e/a ratios varying from 4 to 9).The reasons for the different stereochemical results are discussed.
