18272-88-3Relevant academic research and scientific papers
Ligand-controlled palladium-catalyzed regiodivergent suzuki-miyaura cross-coupling of allylboronates and aryl halides
Yang, Yang,Buchwald, Stephen L.
supporting information, p. 10642 - 10645 (2013/08/23)
An orthogonal set of catalyst systems has been developed for the Suzuki-Miyaura coupling of 3,3-disubstituted and 3-monosubstituted allylboronates with (hetero)aryl halides. These methods allow for the highly selective preparation of either the α- or the
Regioselective cross-coupling of allylboronic acid pinacol ester derivatives with aryl halides via Pd-PEPPSI-IPent
Farmer, Jennifer L.,Hunter, Howard N.,Organ, Michael G.
, p. 17470 - 17473 (2013/01/15)
The cross-coupling reactions of allylboronic acid pinacol ester derivatives with aryl and heteroaryl halides occurred with high selectivity (>97%) at the α-carbon of the allylboron reagent in the presence of Pd-PEPPSI-IPent precatalyst and 5 M KOH in refluxing THF. In the case of trisubstituted allylboronates with different substituents on the olefin, minor olefin geometry isomerization was observed (E/Z & 80/20).
Practical iron-catalyzed allylations of aryl grignard reagents
Mayer, Matthias,Czaplik, Waldemar M.,Von Wangelin, Axel Jacobi
supporting information; experimental part, p. 2147 - 2152 (2010/12/18)
An operationally simple iron-catalyzed reductive cross-coupling reaction between aryl halides and allyl electrophiles has been developed. The underlying domino process exhibits high versatility with respect to the allylic leaving group (acetate, tosylate, diethyl phosphate, methyl carbonate, trimethylsilanolate, methanethiolate, chloride, bromide) and high economic and environmental sustainability with respect to the catalyst system (0.2-5 mol% tris(acetylacetonato)iron(III), ligand-free) and reaction conditions (tetrahydrofuran, 0°C, 45 min).
Photochemical reactivity of α-phenyl β,γ-enones. Singlet 1,3-acyl shift, triplet aromatic di-?-methane (DPM) rearrangement and triplet aryl-carbonyl bridging
Koppes, Margareth J. C. M.,Beentjes, Peter C. J.,Cerfontain, Hans
, p. 313 - 324 (2007/10/02)
The photochemistry of the series of α-phenyl β,γ-enones 6-10 has been studied under conditions of both direct (λ 300 nm) and triplet-sensitized irradiation with the aim of determining the reactivity patterns of these "multi"-chromophoric systems.Upon direct irradiation, the reactants exhibit the typical photoreactions of β,γ-enones, viz. the 1,3-acyl shift, affording the corresponding (E)- and (Z)-5-phenyl-4-hexen-3-ones, decarbonylation of the radicals formed by α-cleavage and recombination of the resulting alkyl radicals and, in addition, a new type of reaction from the triplet-excited state yielding small amounts of the corresponding acetophenones.The acetophenones are thought to be formed by initial β-bridging between the carbonyl and the phenyl group, followed by extrusion of the C4H6 fragment from the 1,4- or 1,3-oxa-diradical.Upon sensitized irradiation, the o-methoxy- and p-cyano-substituted reactants 9 and 10 exhibit the di-?-methane rearrangement, leading to mixtures of the corresponding cis- and trans-1-acetyl-1-methyl-2-phenylcyclopropanes, with quantum yields of 0.03 and 0.10, respectively.The formation of the 1,3-AS and decarbonylation products illustrates the occurrence of α-cleavage, whereas the acetophenones and di-?-methane products are formed via initial aryl-carbonyl and aryl-vinyl bridging, respectively.The inability of the other α-phenyl β,γ-enones to undergo photocyclopropanation is discussed in terms of excitation-energy partition.In the o-methoxy and p-cyano-substituted reactants, the excitation energy may be predominantly concentrated in the aryl moiety in contrast to the other two systems in which the excitation energy may be mainly localized on the β,γ-enone moiety.Subsequent triplet-energy dissipation by a free-rotor mechanism would then account for the stability of these systems.This was observed for (E)-7 which, upon triplet sensitization, affords only the (Z) isomer, whereas this process is degenerate for the other substrates studied.
Reactivity of Aryl Vinyl Di-?-methane Systems. Mechanistic and Exploratory Organic Photochemistry
Zimmerman, Howard E.,Swafford, Richard L.
, p. 3069 - 3083 (2007/10/02)
The di-?-methane rearrangement of a series of meta and para substituted arylvinylmethane reactants was investigated with the aim of determiningthe patterns of reactivity in systems in which initial excitation is localized in the aryl moiety.Thus the photo
