113002-45-2Relevant academic research and scientific papers
Cobalt Mediated Radical Addition-Elimination Carbon-Carbon Bond Forming Reactions in Synthesis
Patel, Vinod F.,Pattenden, Gerald
, p. 871 - 872 (1987)
Alkyl radicals generated by photolytic homolysis of cobalt 'salophen' reagents add to activated carbon-carbon double bonds producing preparatively useful yields of new alkene products; the reactions proceed via radical (Michael) addition, followed by elimination of H-Co.
Twofold carbon-carbon bond formation by intra- and intermolecular radical reactions of aryl diazonium salts
Jasch, Hannelore,Landais, Yannick,Heinrich, Markus R.
, p. 8411 - 8416 (2013/07/11)
Cascade reactions: A variety of novel cascade reactions can be performed when the known and well-studied radical 5- or 6-exo-cyclization of an aryl diazonium salt is conducted in the presence of alkenes and further optional scavengers (see scheme). Copyri
Allylsilanes in "tin-free" oximation, alkenylation, and allylation of alkyl halides
Rouquet, Guy,Robert, Frederic,Mereau, Raphael,Castet, Frederic,Landais, Yannick
supporting information; experimental part, p. 13904 - 13911 (2012/01/15)
Tin-free oximation, vinylation, and allylation of alkyl halides have been developed by using allylsilanes as di-tin surrogates. Initiation of the radical process with a peroxide provides the silyl radical, which can abstract a halogen from the corresponding alkyl halide. The resulting carbon-centered radical then adds to various acceptors, including a sulfonyloxime, a vinylsulfone, and an allylsulfone, leading to formation of the desired products along with the corresponding allylsulfone resulting from the reaction of the PhSO2 radical with the allylsilane precursor. Better results were generally obtained with methallylsilane 1b than with 1a. This observation was rationalized by invoking the higher nucleophilicity of 1b and the faster β-fragmentation of the corresponding β-silyl radical intermediate. Calculation of the energy barrier for the β-fragmentation of a series of β-silyl radicals at the DFT level supported this hypothesis. Finally, a second version of these oximation and vinylation reactions, based on the utilization of 3-tris(trimethylsilyl)silylthiopropene, was devised, affording the desired oximes and olefins in reasonable yields. This strategy allowed the title reaction to be performed under milder conditions (AIBN, benzene, 80°C), as a result of the easier β-fragmentation of the C-S bond as compared with the C-Si bond.
Cobalt-Mediated Intermolecular Radical Additions to Carbon-to-Carbon Double Bonds leading to New Functionalised Alkenes
Bhandal, Harcharan,Howell, Amy R.,Patel, Vinod F.,Pattenden, Gerald
, p. 2709 - 2714 (2007/10/02)
Alkyl radicals generated by photolytic homolysis of cobalt salophen reagents, e.g. (6) and (15), are shown to add to activated carbon-to-carbon double bonds, i.e. ethyl acrylate, methyl vinyl ketone, acrylonitrile, and styrene, producing preparatively useful yields of new alkene products, viz. (9), (10), (12) and (14) , and (16) .The reactions proceed via radical (Michael) additions, followed by 'dehydrocobaltation' from the presumed organocobalt intermediates (2) (Scheme 4).By use of this chemistry, in combination with the Schrauzer 'hydrocobaltation' reaction of alkenes, a new method for the cross-coupling reactions between two alkenes, leading to new functionalised alkenes, e.g. (24), (25), (26), (27), (28), and (29), is developed .
