7605-52-9Relevant 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).
STEREOCHEMICAL CONTROL BY CARBOXYLATE GROUPS IN HOMOGENEOUS HYDROGENATION
Brown, John M.,Hall, Stephen A.
, p. 333 - 342 (2007/10/02)
The stereochemistry of hydrogenation of a range of unsaturated cyclohexane-carboxylic acids and their esters has been investigated, employing either bis(1,4-diphenylphosphino)butanerhodium or pyridine(tricyclohexylphosphine)iridium based cationic catalysts in CH2Cl2.For methyl 3-methylcyclohex-2-enecarboxylate, highly selective reduction to the trans-product was achieved in both cases, whereas the isomeric methyl 3-methylenecyclohexanecarboxylate gave appreciable amounts of the cis-isomer.A predominance of trans-isomer was also achieved in the reduction of methyl 4-methylcyclohex-3-ene carboxylate, in a rather slower reaction.Reductions with D2 revealed that considerable isomerisation of the olefinic double bond occurred during hydrogenation.The corresponding unsaturated acids were reduced with moderate to high selectivity but reaction was either very slow, or ceased after a few turnovers.Related cyclohexadienecarboxylates were unreactive to homogeneous hydrogenation with cationic catalysts.
STUDIES OF COMPOUNDS IN THE MENTHANE SERIES. XIX. SYNTHESIS AND PROPERTIES OF TRANS-o-4-MENTHEN-8-OL AND STEREOISOMERIC o-5-METHEN-8-OLS
Bazyl'chik, V. V.,Fedorov, P. I.,Klyuev, N. A.,Dank, E. Kh.
, p. 1320 - 1327 (2007/10/02)
Trans-o-4-Menthen-8-ol and cis- and trans-o-5-menthen-8-ols have been prepared via the Diels-Alder reactions of 1,3-butadiene with crotonaldehyde in the presence of boron trifluoride etherate, and piperylene with methyl acrylate, respectively.The dehydration reactions of these alcohols have been studied in the presence of acetic anhydride and potassium bisulfate; the latter reagent demonstrates a high reaction selectivity.
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.
