10.1021/jo00231a046
The research focuses on the development of a more efficient and convenient method for allylic and benzylic oxidations using a reagent system comprised of tert-butyl hydroperoxide and pyridinium dichromate. The purpose of this study was to address the drawbacks of traditional chromium(VI)-based oxidation methods, such as the use of large excess reagents, large volumes of solvents, and long reaction times. The researchers found that the combination of these two reagents in a 1:1 molar ratio effectively facilitated the oxidation process under mild conditions, yielding high conversion rates and product yields. The chemicals used in the process included tert-butyl hydroperoxide, pyridinium dichromate, and various substrates such as cholesteryl acetate, dicyclopentadiene, citronellol acetate, 1-phenylcyclohexene, α-pinene, A3-carene, cycloheptene, limonene, fluorene, diphenylmethane, and tetralin, among others. The conclusions of the research highlighted the utility and simplicity of the tert-butyl hydroperoxide-pyridinium dichromate method, suggesting its potential for wide application in organic synthesis.
10.1021/jo00343a001
The research focuses on the molten salt catalyzed transfer hydrogenation of polycyclic aromatic hydrocarbons, specifically the selective hydrogenation of anthracene and naphthacene by tetralin in the presence of molten antimony trichloride (SbCl3) as a catalyst at 80°C. The study aims to understand the redox-initiated ionic mechanism involving the arene radical cation and the 1-tetralyl cation as key intermediates in these transfer hydrogenation reactions. The conclusions drawn from the research indicate that anthracene and naphthacene are selectively hydrogenated to 9,10-dihydroanthracene and 5,12-dihydronaphthacene, respectively, without forming naphthalene, and instead, the dehydrogenated tetralin reacts with itself and unreacted arene to give alkylated products. The chemicals used in this process include anthracene, naphthacene, tetralin, and molten SbCl3, with additional compounds such as phenanthrene, pyrene, and perylene being tested under similar conditions to understand their reactivity patterns.
10.1039/b313491a
The research examines the thermal decomposition of various O-benzyl ketoxime ethers (R1R2C(NOCH2Ph)) in three hydrogen donor solvents: tetralin, 9,10-dihydrophenanthrene (DHP), and 9,10-dihydroanthracene (DHA). The study aims to understand the dominant homolytic cleavage modes and the effects of substituents and solvents on the dissociation processes. The results show that the yields of products like imines and benzyl alcohol varied with the solvent, indicating significant involvement of reverse radical disproportionation (RRD) in DHP and DHA, where hydrogen atoms from the solvent transfer to the oxime ethers, followed by β-scission of the resultant radicals. In tetralin, an additional product, benzaldehyde, was observed, suggesting an alternative decomposition mode involving benzylic hydrogen abstraction. The study concludes that the RRD process plays a crucial role in the thermal decomposition of these oxime ethers in certain solvents, and the rates of decomposition and product yields are influenced by both the nature of the substituents and the solvent used.
10.1039/c9cc03509e
The research focuses on the acid-catalyzed chirality-transferring intramolecular Friedel-Crafts cyclization of optically active α-hydroxy-α-alkenylsilanes, which are compounds containing a benzene ring and a silyl group. The purpose of this study is to synthesize enantiopure organic molecules, a significant challenge in organic synthesis, by leveraging the chirality transfer from a chiral allyl alcohol to a tetrahydronaphthalene product. The researchers used trimethylsilyl trifluoromethanesulfonate (TMSOTf) as a Lewis acid catalyst and found that it effectively promoted the cyclization reaction, yielding vinylsilane-tethered tetrahydronaphthalenes with high optical purity (up to 98% ee).