7661-39-4Relevant articles and documents
Tetraphosphine/palladium catalysed Suzuki cross-coupling reactions of aryl halides with alkylboronic acids
Kondolff, Isabelle,Doucet, Henri,Santelli, Maurice
, p. 3813 - 3818 (2007/10/03)
Through the use of [PdCl(C3H5)]2/cis,cis, cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as a catalyst, a range of aryl bromides and chlorides undergoes Suzuki cross-coupling with alkylboronic acids in good yields. Several alkyl substituents such as ethyl, n-butyl, n-octyl, isobutyl or 2,2-dimethylpropyl on the alkylboronic acids have been successfully used. The functional group tolerance on the aryl halide is remarkable; substituents such as fluoro, methyl, methoxy, acetyl, formyl, benzoyl, nitro or nitrile are tolerated. Furthermore, this catalyst can be used at low loading, even for reactions of sterically hindered aryl bromides.
Nucleophilic Character of the Alkyl Radicals. 19. Absolute Rate Constants in the Homolytic Alkylation of Protonated Heteroaromatic Bases by n-Butyl and tert-Butyl Radicals
Citterio, Attilio,Minisci, Francesco,Franchi, Valeria
, p. 4752 - 4757 (2007/10/02)
The rate constants for the homolytic alkylation of protonated heteroaromatic bases (quinoline, pyridine, and 4-cyano-, 4-acetyl-, 4-methyl-, and 4-methoxypyridine) by n-butyl and tert-butyl radicals were measured at 57 deg C by competition of the aromatic addition with the alkyl radical oxidation by Cu2+ salts (for which the rates are known).With the more activated substrates (quinoline and 4-cyano- and 4-acetylpyridine) the tert-butyl radical is significantly more reactive then the n-butyl radical, clearly showing that polar effects are more important than steric and enthalpic effects in determining the reaction rates.The reversibility of the alkylation by the tert-butyl radical is discussed.
