6013-92-9Relevant academic research and scientific papers
Hydrogen-bonded networks in 1-(4-methoxyphenyl)-2,2-dimethyl-propan-1-ol
Glinski, Marek,Wilczkowska, Ewa,Madura, Izabela D.,Zachara, Janusz
, p. o720-o722 (2007)
The asymmetric unit of the title compound, C12H18O2, contains two independent mol-ecules. They differ only slightly in conformation but form completely different inter-molecular hydrogen-bonded arrays. One molecule exhibits disorder in the hydroxy group r
Arylboronic Acid Catalyzed C-Alkylation and Allylation Reactions Using Benzylic Alcohols
Estopi?á-Durán, Susana,McLean, Euan B.,Donnelly, Liam J.,Hockin, Bryony M.,Taylor, James E.
supporting information, p. 7547 - 7551 (2020/10/09)
The arylboronic acid catalyzed dehydrative C-alkylation of 1,3-diketones and 1,3-ketoesters using secondary benzylic alcohols as the electrophile is reported, forming new C-C bonds (19 examples, up to 98% yield) with the release of water as the only byproduct. The process is also applicable to the allylation of benzylic alcohols using allyltrimethylsilane as the nucleophile (12 examples, up to 96% yield).
Photochemical oxidation of benzylic primary and secondary alcohols utilizing air as the oxidant
Nikitas, Nikolaos F.,Tzaras, Dimitrios Ioannis,Triandafillidi, Ierasia,Kokotos, Christoforos G.
, p. 471 - 477 (2020/02/13)
A mild and green photochemical protocol for the oxidation of alcohols to aldehydes and ketones was developed. Utilizing thioxanthenone as the photocatalyst, molecular oxygen from air as the oxidant and cheap household lamps or sunlight as the light source, a variety of primary and secondary alcohols were converted into the corresponding aldehydes or ketones in low to excellent yields. The reaction mechanism was extensively studied.
Nickel-Catalyzed Addition of Aryl Bromides to Aldehydes to Form Hindered Secondary Alcohols
Garcia, Kevin J.,Gilbert, Michael M.,Weix, Daniel J.
supporting information, p. 1823 - 1827 (2019/02/14)
Transition-metal-catalyzed addition of aryl halides across carbonyls remains poorly developed, especially for aliphatic aldehydes and hindered substrate combinations. We report here that simple nickel complexes of bipyridine and PyBox can catalyze the addition of aryl halides to both aromatic and aliphatic aldehydes using zinc metal as the reducing agent. This convenient approach tolerates acidic functional groups that are not compatible with Grignard reactions, yet sterically hindered substrates still couple in high yield (33 examples, 70% average yield). Mechanistic studies show that an arylnickel, and not an arylzinc, adds efficiently to cyclohexanecarboxaldehyde, but only in the presence of a Lewis acid co-catalyst (ZnBr2).
Forming tertiary organolithiums and organocuprates from nitrile precursors and their bimolecular reactions with carbon electrophiles to form quaternary carbon stereocenters
Schnermann, Martin J.,Untiedt, Nicholas L.,Jiménez-Osés, Gonzalo,Houk, Kendall N.,Overman, Larry E.
supporting information, p. 9581 - 9586 (2012/11/14)
Unstabilized tertiary organolithium intermediates are conveniently generated by reductive decyanation of nitriles, and these reagents and their derived cuprates couple in useful yields with carbon- centered electrophiles (see example). Chiral tertiary org
Copper-catalyzed hydrosilylation with a bowl-shaped phosphane ligand: Preferential reduction of a bulky ketone in the presence of an aldehyde
Fujihara, Tetsuaki,Semba, Kazuhiko,Terao, Jun,Tsuji, Yasushi
supporting information; experimental part, p. 1472 - 1476 (2010/05/02)
Chemical Equation Presented Hollywood bowl: A highly active copper catalyst with a bowl-shaped phosphane (bsp) ligand was used in the hydrosilylation reaction of bulky ketones. The preferential reduction of a bulky ketone in the presence of an unprotected aldehyde is unprecedented.
Tuning the reactivity of O-tert-butyldimethylsilylimidazolyl aminals towards organolithium reagents
Gimisis, Thanasis,Arsenyan, Pavel,Georganakis, Dimitris,Leondiadis, Leondios
, p. 1451 - 1454 (2007/10/03)
O-tert-Butyldimethylsilylimidazolyl aminals are N,O-acetals that form readily from aldehydes, and although they function as aldehyde stabilizing and protecting groups under various conditions, we report here that they react with organolithium reagents similarly to the parent aldehydes. The mechanism involves the intermediate formation of a 2-imidazolyl anion as is exemplified by the isolation of 2-TBDMS-imidazole. Substitution of the imidazolyl moiety at the 2-position renders these aldehyde derivatives stable to organolithium reagents, thus allowing for the tuning of their reactivity.
Side-chain fragmentation of arylalkanol radical cations. Carbon-carbon and carbon-hydrogen bond cleavage and the role of α- and β-OH groups
Baciocchi, Enrico,Bietti, Massimo,Putignani, Lorenza,Steenken, Steen
, p. 5952 - 5960 (2007/10/03)
A product analysis and kinetic study of the one-electron oxidation of a number of 1-arylpropanols, 1,2-diarylethanols, and some of their methyl ethers by potassium 12-tungstocobaltate(III) (abbreviated as Co(III)W) in aqueous acetic acid was carried out and complemented by pulse radiolysis experiments. The oxidations occur via radical cations which undergo side-chain fragmentation involving the C(α)-H and/or C(α)-C(β) bond. With 1-(4-methoxyphenyl)-2-methoxypropane (1), only deprotonation of the radical cation is observed. In contrast, removing the ring methoxy group leads to exclusive C-C bond cleavage in the radical cation. Replacing the side-chain β-OMe by β-OH, the radical cation undergoes both C-C and C-H bond cleavage, with both pathways being base catalyzed. C-C bond breaking in the radical cation is also enhanced by an α-OH group, as shown by 1-(4-methoxyphenyl)-2,2-dimethyl-1-propanol (7), where this pathway, which is also base catalyzed, is the only one observed. Interestingly, α- and β-OH groups exhibit a very similar efficiency in assisting the C-C bond cleavage route in the radical cations, as is evident from the kinetic and products study of the oxidation of 1-phenyl-2-(4-methoxyphenyl)ethanol (5) and 1-(4-methoxyphenyl)-2-phenylethanol (6) by Co(III)W, and from pulse radiolysis experiments on 5 and 6. C-C bond cleavage is the main reaction for both radical cations which exhibit a very similar rate of fragmentation (k = 2.0 and 3.2 x 104 s-1, respectively). In both fragmentation reactions a small solvent isotope effect, k(H2O)/k(D2O) (1.4 for 5.+ and 1.2 for 6.+) and negative activation entropies are observed. These data suggest that a key role in the assistance by α- or β-OH groups to C-C bond cleavage is played by hydrogen bonding or specific solvation of these groups. The kinetic study of the oxidations promoted by Co(III)W has also shown that when only one group, OH or OMe, is present in the side chain (either on C(α) or C(β)), the fragmentation step or both the electron transfer and fragmentation steps contribute to the overall oxidation rate. However, with an OH group on both carbons of the scissile bond, as in 1-(4-methoxyphenyl)-1,2-propanediol (9), the rate of C-C bond cleavage is so fast that the electron transfer step becomes rate determining.
Synthesis of 3-(4'-Methoxyphenyl)-2,2,4,4-tetramethylpentane and Some Cyclic Analogues
Collins, David J.,Jacobs, Howard A.
, p. 2095 - 2110 (2007/10/02)
Reaction of 1-methoxy-2-methyl-1-trimethylsilyloxyprop-1-ene (8) with 1-acetoxy-1-(4'-methoxyphenyl)-2,2-dimethylpropane (7b) in the presence of zinc iodide gave 84percent of methyl 3-(4'-methoxyphenyl)-2,2,4,4-tetramethylpentanoate (9a), which was reduce
CHROMATOGRAPHIC RESOLUTION OF ALKYL ARYL CARBINOLS ON A SILICA-SUPPORTED QUININE CHIRAL STATIONARY PHASE
Pini, Dario,Rosini, Carlo,Bertucci, Carlo,Altemura, Paolo,Salvadori, Piero
, p. 603 - 606 (2007/10/02)
Several alkyl aryl carbinols can be separated in enantiomers by liquid chromatography upon a new chiral support, prepared by reaction of γ-mercaptopropylsilanized silica with quinine.From the elution order obtained by means of a circular dichroism detecto
