172990-75-9Relevant academic research and scientific papers
Retention of regiochemistry of monosubstituted allyl acetates in the ruthenium catalysed allylic alkylation with malonate anion
Kawatsura, Motoi,Ata, Fumio,Hayase, Shuichi,Itoh, Toshiyuki
, p. 4283 - 4285 (2007)
In the RuCl2(p-cymene)/PPh3 catalysed regioselective allylic alkylation of monosubstituted allyl acetates with malonate anion, the selective substitution at the position originally substituted with acetate was observed. The Royal Society of Chemistry.
Allylic C-H acetoxylation with a 4,5-diazafluorenone-ligated palladium catalyst: A ligand-based strategy to achieve aerobic catalytic turnover
Campbell, Alison N.,White, Paul B.,Guzei, Ilia A.,Stahl, Shannon S.
supporting information; experimental part, p. 15116 - 15119 (2011/01/06)
Pd-catalyzed C-H oxidation reactions often require the use of oxidants other than O2. Here we demonstrate a ligand-based strategy to replace benzoquinone with O2 as the stoichiometric oxidant in Pd-catalyzed allylic C-H acetoxylation. Use of 4,5-diazafluorenone (1) as an ancillary ligand for Pd(OAc)2 enables terminal alkenes to be converted to linear allylic acetoxylation products in good yields and selectivity under 1 atm O 2. Mechanistic studies have revealed that 1 facilitates C-O reductive elimination from a π-allyl-PdII intermediate, thereby eliminating the requirement for benzoquinone in this key catalytic step.
Mechanistic investigations of bipyrimidine-promoted palladium-catalyzed allylic acetoxylation of olefins
Lin, Bo-Lin,Labinger, Jay A.,Bercaw, John E.
experimental part, p. 264 - 271 (2009/10/23)
Several pyridine-like ligands were found to improve Pd(OAc) 2-catalyzed allylic oxidation of allylbenzene to cinnamyl acetate by p-benzoquinone in acetic acid. The best ligand examined, bipyrimidine, was used to identify the catalyst precursor for this system, (bipyrimidine)Pd(OAc) 2, which was fully characterized. Mechanistic studies suggest the reaction takes place through disproportionation of (bipyrimidine)Pd(OAc) 2 to form a bipyrimidine-bridged dimer, which reacts with olefin to form a PdII-olefin adduct, followed by allylic C-H activation to produce (η3-allyl)PdII species. The (η3-allyl)PdII intermediate undergoes a reversible acetate attack to generate a Pd0-(allyl acetate) adduct, which subsequently reacts with p-benzoquinone to release allyl acetate and regenerate (bipyrimidine)Pd(OAc)2. No KIE is observed for the competition experiment between allylbenzene-d0 and allylbenzene-d5 (CD2=CDCD2C6H5), suggesting that allylic C-H activation is not rate-determining. Catalytic allylic acetoxylations of other terminal olefins as well as cyclohexene were also effected by (bipyrimidine)Pd(OAc)2.
Direct, iridium-catalyzed enantioselective and regioselective allylic etherification with aliphatic alcohols
Ueno, Satoshi,Hartwig, John F.
, p. 1928 - 1931 (2008/12/22)
(Chemical Equation Presented) From alcohol to ether: Iridium-catalyzed allylations yield α chiral ether derivatives directly from aliphatic alcohols with a simple alkali metal base (see equation). These reactions form ethers from primary, secondary, and tertiary alkoxides with high enantioselectivity. By-products from isomerization were suppressed by the use of an alkyne additive.
Ruthenium-catalysed linear-selective allylic alkylation of allyl acetates
Kawatsura, Motoi,Ata, Fumio,Wada, Shohei,Hayase, Shuichi,Uno, Hidemitsu,Itoh, Toshiyuki
, p. 298 - 300 (2007/10/03)
The regioselectivity in the ruthenium-catalysed allylic alkylation of mono substituted allyl acetates with the malonate anion was highly controlled by Ru3(CO)12 with 2-(diphenylphosphino)benzoic acid, and the linear-type alkylated product was obtained. The Royal Society of Chemistry.
Synthesis and anti-HIV activity of novel N-1 side chain-modified analogs of 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine (HEPT)
Pontikis, Renée,Benhida, Rachid,Aubertin, Anne-Marie,Grierson, David S.,Monneret, Claude
, p. 1845 - 1854 (2007/10/03)
A series of 33 N-1 side chain-modified analogs of 1-[(2- hydroxyethoxy)methyl]-6-(phenylthio)thymine (1, HEPT) were synthesized and evaluated for their anti-HIV-1 activity. In particular, the influence of substitution of the terminal hydroxy group of the acyclic structure of HEPT and the structural rigidity of this side chain were investigated. Halo (7, 8), azido (9), and amino (10-15) derivatives were synthesized from HEPT via the p-tosylate derivative 6. Acylation of the primary amine 15 afforded the amido analogs 16-20. The diaryl derivatives 26-29 were prepared by reaction of HEPT, or of the 6-(2-pyridylthio) analog 23, with diaryl disulfides in the presence of tri-n-butylphosphine. Compounds 39-41, in which the N-1 side chain is rigidified by incorporation of an E-configured double bond, were obtained by palladium(0)-catalyzed coupling of several different 6- (arylthio)uracil derivatives (37, 38) with allyl acetates 33. Compounds 13, 40a,c,d,f, and 41, incorporating an aromatic ring at the end of the acyclic side chain, were found to be more potent than the known diphenyl-substituted HEPT analog BPT (2), two of them, 40c,d, being 10-fold more active.
The Effect of Solvent and Copper(I) Precursor on the Regioselectivity in the Cross-Coupling Reaction of Primary Allylic Acetates with Preformed Mono- and Dibutylcuprates
Persson, Eva S. M.,Baeckvall, Jan-E.
, p. 899 - 906 (2007/10/03)
The reactions between preformed organocopper compounds and primary allylic acetates show that the solvent and the copper(I) precursor are important parameters in determining the regioselectivity of the reaction.The organocopper complexes were prepared from different copper(I) salts, such as CuCl, CuBr, CuI and CuCN, and their reactivity both in Et2O and THF were studied.In THF, monobutylcuprates gave the γ-substituted product whereas the dibutylcuprates afforded the α-substituted product.In Et2O, cuprates formed from CuCN and CuI gave γ-selective reactions whereas those from CuCl and CuBr resulted in α-selective reactions.
