13295-90-4Relevant academic research and scientific papers
A METHOD FOR THE PALLADIUM-CATALYZED ALLYLIC OXIDATION OF OLEFINS
McMurry, John E.,Kocovsky, Pavel
, p. 4187 - 4190 (1984)
Olefins are converted into allylic acetates by treatment in acetic acid with a catalytic amount of palladium bis(trifluoroacetate) and one equivalent of benzoquinone as oxidant.The reaction is selective for oxidation of a terminal methyl group of geranylacetone.
Carbon-13 pulse fourier transform NMR. Conformational preference of the hydroxyl and the acetoxyl group in 2-methyl-2-cyclohexenol and its acetate
Senda,Imaizumi,Ochiai,Fujita
, p. 539 - 541 (1974)
13C Fourier transform NMR of cis and trans 5 - t - butyl - 2 - methyl - 2 - cyclohexenol, 2 -methyl - 2 - cyclohexenol and their acetates has been examined indicating that the pseudo-axial orientation of the hydroxyl and the acetoxyl group at t
Efficient palladium-catalyzed nucleophilic addition of triorganoindium reagents to carbocyclic derivatives
Baker, Lucas,Minehan, Thomas
, p. 3957 - 3960 (2007/10/03)
Palladium (0)-catalyzed allylic substitution reactions employing triorganoindium reagents have been investigated. In situ generated vinyl- and arylindiums react with substituted and unsubstituted cyclohex-2-enyl esters in the presence of 1-3 mol % Pd2(dba)3 to produce vinyl- or arylcyclohexenes in moderate to excellent yields. The stereoselectivity of this process was also examined, and evidence is presented that the reaction proceeds with inversion of stereochemical configuration.
Oxidative esterification of alkenes via π- and σ-organopalladium complexes: New pathways for the reaction
Kozitsyna, N.Yu.,Bukharkina,Martens,Vargaftik,Moiseev
, p. 69 - 75 (2007/10/03)
New mechanistic data on the oxidative esterification of alkenes were obtained in the study of the reaction of Pd(II) acetate with hex-1-ene, methylcyclohex-1-ene and racemic α-pinene in a chloroform solution. High yields of unsaturated esters with terminal alcohol group were found in the oxidation of hex-1-ene, while the exocyclic methyl groups in methylcyclohex-1-ene and α-pinene remain untouched.
Efficient and recyclable monomeric and dendritic Ru-based metathesis catalysts
Garber, Steven B.,Kingsbury, Jason S.,Gray, Brian L.,Hoveyda, Amir H.
, p. 8168 - 8179 (2007/10/03)
Several highly active, recoverable and recyclable Ru-based metathesis catalysts are presented. The crystal structure of Ru complex 5, beating a 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene and styrenyl ether ligand is disclosed. The heterocyclic ligand significantly enhances the catalytic activity, and the styrenyl ether allows for the easy recovery of the Ru complex. Catalyst 5 promotes ring-closing metathesis (RCM) and the efficient formation of various trisubstituted olefins at ambient temperature in high yield within 2 h; the catalyst is obtained in >95% yield after silica gel chromatography and can be used directly in subsequent reactions. Tetrasubstituted olefins can also be synthesized by RCM reactions catalyzed by 5. In addition, the synthesis and catalytic activities of two dendritic and recyclable Ru-based complexes are disclosed (32 and 33). Examples involving catalytic ring-closing, ring-opening, and cross metatheses are presented where, unlike monomer 5, dendritic 33 can be readily recovered.
Synthetic studies towards (+)-Dihydroampullicin. Michael addition of N-Boc-2-(tert-butyldimethylsiloxy)-3-methyl-pyrrole to α-methylene lactones
Marcos,Redero,Bermejo
, p. 8451 - 8455 (2007/10/03)
The Michael addition of N-(tert-butoxycarbonyl)-2-(tert-butyldimethylsiloxy)-3-methyl-pyrrole (4) to several α-methylene lactones catalyzed by fluoride ions yielded the corresponding homologated products (26-30) with good yields. Application of this react
Reaction of cyclic allylic acetates with aliphatic alcohols in the presence of cerium(III) chloride
Uzarewicz,Dresler
, p. 1921 - 1930 (2007/10/03)
The reactions of selected allylic acetates with methanol, ethanol, n-propyl alcohol, isopropyl alcohol and tert-butyl alcohol in the presence of catalytic amounts of cerium(III) chloride are described. Allylic alkyl ethers, bis-allylic ethers and 1,3-dienes were obtained depending on the structure of the acetates.
Pd-containing catalytic system for oxidative acetoxylation of alkenes
Romanenko,Tormyshev,Shteingarts
, p. 1549 - 1562 (2007/10/03)
Four-substituted cyclohexenes were used as examples for revealing the substituent effect on composition of products obtained by oxidative acetoxylation of alkenes catalyzed with Pd(II) acetate. The distribution of products is rationalized on assumption of relative stability of allylic anions and steric strains in (π-allyl)palladium intermediates. Stereoselective yield of trans-substituted endo-acetates is due to stabilizing effect of lower unoccupied orbital of the forming C-OAc bond and occupied orbitals of pseudoaxial C-H bonds at the cycle in the transition states. The substrates capable of this reaction are limited to alkenes with insignificant steric shielding of the double bond. The study of the influence on the process of the characteristics of oxidant used in the catalytic system revealed that the most significant difference is observed between catalysts prepared as homogeneous oxidative systems and those containing heterogeneous oxidant MnO2 or TiO2 as additive. 1998 MAHK "Hayka/Interperiodica".
Process for the preparation of carboxylic esters defined from allylic alcohols
-
, (2008/06/13)
A process which comprises reacting an aliphatic or cycloaliphatic olefin, having 4 to 16 carbon atoms in its main chain and a non-terminal double bond, with a carboxylic acid, in the presence of hydrogen peroxide and a catalyst consisting of a palladium salt or complex.
A Regioselective and Stereospecific Synthesis of Allylsilanes from Secondary Allylic Alcohol Derivatives
Fleming, Ian,Higgins, Dick,Lawrence, Nicholas J.,Thomas, Andrew P.
, p. 3331 - 3350 (2007/10/02)
Primary and secondary allylic acetates and benzoates react with the dimethyl(phenyl)silyl-cuprate reagent to give allylsilanes, provided that the THF in which the cuprate is prepared is diluted with ether before addition of the allylic ester.The reaction is reasonably regioselective in some cases: (i) when the allylic system is more-substituted at one end than the other, as in the reactions 4->5 and 9->10; (ii) when the steric hindrance at one end is neopentyl-like, as in the reactions 15->16; and (iii) when the disubstituted double bond has the Z configuration, as in th e reactions Z-19->E-21 or, better, because the silyl group is becoming attached to the less-sterically hindered end of the allylic system, Z-20->E-22.The regioselectivity is better if a phenyl carbamate is used in place of the ester, and a three-step protocol assembling the mixed cuprate on the leaving group is used, as in the reactions 23->24 and E- or Z-29->E-21, or, best of all, because the silyl group is again becoming attached to the less-sterically hindered end of the allylic system, E- or Z-30->E-22.This sequence works well to move the silyl group onto the more substituted end of an allyl system, but only when the move is from a secondary allylic carbamate to a tertiary allylsilane, as in the reaction 38->39.Allyl(trimethyl)silanes can be made using alkyl- or aryl-cuprates on trimethylsilyl-containing allylic esters and carbamates, as in the reactions 40->41, and 43->44.The reaction of the silyl-cuprate with allylic esters and the three-step sequence with the allylic carbamates are stereochemically complementary, the former being stereospecifically anti and the latter stereospecifically syn.Homochiral allylsilanes can be ma de by these methods with high levels of stereospecificity, as shown by the synthesis of the allylsilanes 54, 58 and 59.
