- Synthesis of Ketones and Esters from Heteroatom-Functionalized Alkenes by Cobalt-Mediated Hydrogen Atom Transfer
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Cobalt bis(acetylacetonate) is shown to mediate hydrogen atom transfer to a broad range of functionalized alkenes; in situ oxidation of the resulting alkylradical intermediates, followed by hydrolysis, provides expedient access to ketones and esters. By modification of the alcohol solvent, different alkyl ester products may be obtained. The method is compatible with a number of functional groups including alkenyl halides, sulfides, triflates, and phosphonates and provides a mild and practical alternative to the Tamao-Fleming oxidation of vinylsilanes and the Arndt-Eistert homologation.
- Ma, Xiaoshen,Herzon, Seth B.
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p. 8673 - 8695
(2016/10/17)
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- Synergistic steric effects in the development of a palladium-catalyzed alkyne carbohalogenation: Stereodivergent synthesis of vinyl halides
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We report our finding that by exploiting the synergistic steric effects between substrate and catalyst, an intramolecular Pd-catalyzed alkyne carbohalogenation can be achieved. This operationally simple method uses the bulky Pd/ Q-Phos combination and all
- Le, Christine M.,Menzies, Perry J. C.,Petrone, David A.,Lautens, Mark
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supporting information
p. 254 - 257
(2015/02/19)
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- Dual gold catalysis: A novel synthesis of bicyclic and tricyclic pyrroles from n -propargyl ynamides
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Various N-propargyl ynamides were converted to bicylic and tricyclic pyrroles by the use of a cationic dual-activation gold catalyst. This reaction starts with the nucleophilic addition of a gold acetylide onto an ynamide triple bond at the ?2-position of the nitrogen atom. Thus, gold vinylidene is formed, and then a second cyclization takes place. The formation of the gold vinylidene is indicated by the evidence that not only aryl ynamides but also alkyl ynamides undergo C-H activation in these reactions.
- Tokimizu, Yusuke,Wieteck, Marcel,Rudolph, Matthias,Oishi, Shinya,Fujii, Nobutaka,Hashmi, A. Stephen K.,Ohno, Hiroaki
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supporting information
p. 604 - 607
(2015/03/05)
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- Keteniminium ion-initiated cascade cationic polycyclization
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A novel and efficient keteniminium-initiated cationic polycyclization is reported. This reaction, which only requires triflic acid or bistriflimide as promoters, affords a straightforward entry to polycyclic nitrogen heterocycles possessing up to three co
- Theunissen, Cdric,Mtayer, Benot,Henry, Nicolas,Compain, Guillaume,Marrot, Jrome,Martin-Mingot, Agns,Thibaudeau, Sbastien,Evano, Gwilherm
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supporting information
p. 12528 - 12531
(2014/12/10)
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- Synthesis and reactivity of aryl(alkynyl)iodonium salts
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The first practical, yet simple, preparation of aryl(alkynyl)iodonium trifluoroacetate salts is described. The generic nature of this synthetic method has allowed the production of a range of aryl(alkynyl)iodonium trifluoroacetate salts with independent variation of both the alkynyl and aryliodo groups in yields of 30-85 %. Application of these new reagents to the synthesis of a series of 2-arylfuro[3,2-c]pyridines (40-64 %) highlights the potential of this class of materials as precursors to bioactive heterocyclic structures. These experiments have also demonstrated that, in this case, the effect of the aryliodo group on the reaction is negligible.
- Dixon, Luke I.,Carroll, Michael A.,Gregson, Thomas J.,Ellames, George J.,Harrington, Ross W.,Clegg, William
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supporting information
p. 2334 - 2345
(2013/05/21)
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- Reactions with Phosphinealkylenes, XXXIX. - New Methods for the Preparation of 1-Bromoacetylenes and Enynes
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1,1-Dibromoolefins 4 are obtained in good yield from the reaction of aldehydes 1 with triphenylphosphane (2) and carbon tetrabromide (3).Reaction of 4 with three moles of methylene(triphenyl)phosphorane (8) leads to the propargylidene(triphenyl)phosphoranes 11 which react with aldehydes to give the enynes 13.The ylides 11 can also prepared via the reaction of bromoacetylenes 7, which can be obtained from 4, with two moles of 8.This reaction sequence allows the synthesis of new retinoids with enyne structures from retinal.
- Bestmann, Hans Juergen,Frey, Herbert
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p. 2061 - 2071
(2007/10/02)
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