A General and Efficient Palladium-Catalyzed Alkoxycarbonylation of Phenols To Form Esters through In Situ Formed Aryl Nonaflates
作者:Xiao-Feng Wu、Helfried Neumann、Matthias Beller
DOI:10.1002/chem.201103797
日期:2012.3.26
Esters made easy! A general and efficient methodology for the palladium‐catalyzed alkoxycarbonylation of in situ formed aryl nonaflates has been developed (see scheme). Both homo‐ and cross‐esterifications are possible. DPPF=1,1′‐bis(diphenylphosphino)ferrocene.
Design, Synthesis, and Anticancer Properties of Novel Benzophenone-Conjugated Coumarin Analogs
作者:V. Lakshmi Ranganatha、Farhan Zameer、S. Meghashri、N. D. Rekha、V. Girish、H. D. Gurupadaswamy、Shaukath Ara Khanum
DOI:10.1002/ardp.201300298
日期:2013.12
of anticancer drugs with specific targets is of prime importance in modern chemical biology. Observing the importance of benzophenone and coumarin nucleus, it would be worthwhile to design and synthesize novel benzophenone derivatives (8a–o) bearing the coumarin nucleus. Further, they were screened for prospective anticancer activities in vitro against the Michigan Cancer Foundation‐7 (MCF‐7) and Ehrlich's
An unprecedented synergistic effect, obtained for rationally designed AuâPd alloy nanoparticles supported on an acidic metalâorganic framework (MOF), in the aerobic oxidation of the primary CâH bonds in toluene and derivates is reported.
Aryl radicals from organometallic sources. Preferential attack on the side chain of toluenes by the o-tolyl radical
作者:Luigi Pietro Battaglia、Mario Nardelli、Corrado Pelizzi、Giovanni Predieri、Gian Paolo Chiusoli
DOI:10.1016/0022-328x(86)80528-9
日期:1986.12
The o-tolyl radicals, formed by the reaction of o-chlorotoluene with [Mo(N2)2-(dppe)2] (dppe = Ph2PCH2CH2PPh2) or by the decomposition of o-toluoyl peroxide, preferentially attack the methyl group of toluenes giving rise to bibenzyls. In contrast the m- and p-tolyl radicalspreferentially attack the aromatic nucleus.
Intramolecular Hydrogen-Atom Transfer in 2-Alkylbenzoyloxyl Radicals as Studied by Transient Absorption Kinetics and Product Analyses on the Photodecomposition of Bis(2-alkylbenzoyl) Peroxides
The pulsed-laser excitation of bis(2-methylbenzoyl) peroxide at 308 nm in acetonitrile afforded a broad absorption band at 500—800 nm due to 2-methylbenzoyloxyl radicals. The decay of this band accompanied the growth of another band at 350 nm due to 2-carboxybenzyl radicals produced by an intramolecular hydrogen-atom transfer from the neighboring 2-methyl group; the rate constant was 1.7 × 107 s−1 at 23 °C, the activation energy and frequency factor being 17 kJ mol−1 and 1010.5 s−1, respectively. The rates for intramolecular hydrogen-atom transfer in 2-MeCH2C6H4CO2· and 2-PhCH2C6H4CO2· are much higher than that in 2-CH3C6H4CO2·, since the parent peroxides, (2-MeCH2C6H4CO2)2 and (2-PhCH2C6H4CO2)2, exhibited only 350-nm bands ascribable to the corresponding 2-carboxybenzyl radicals, even immediately after laser excitation.The pulsed-laser photolyses of the above-mentioned peroxides afforded PhCH2R, 2-HOCOC6H4CH(R)CH2CN, and 2-HOCOC6H4CHRCHRC6H4CO2H-2 (R = H, Me, and Ph) as the main products in acetonitrile. The formation of PhCH2R is explained in terms of the contribution of two-bond fission of the O–O and C(α)–C bonds of the peroxide in the excited singlet state in competition with O–O bond cleavage followed by an intramolecular hydrogen-atom transfer.