123005-19-6Relevant articles and documents
Unprotected Amino Acids as Stable Radical Precursors for Heterocycle C-H Functionalization
Mai, Duy N.,Baxter, Ryan D.
supporting information, p. 3738 - 3741 (2016/08/16)
An efficient and general method for the C-H alkylation of heteroarenes using unprotected amino acids as stable alkyl radical precursors is reported. This one-pot procedure is performed open to air under aqueous conditions and is effective for several natural and unnatural amino acids. Heterocycles of varying structure are suitably functionalized, and reactivity trends reflect the nucleophilic character of the radical species generated.
New General Processes of Homolytic Alkylation of Heteroaromatic Bases by t-BuOOH or (t-BuO)2 and Alkyl Iodides
Fontana, Francesca,Minisci, Francesco,Barbosa, Maria Claudia Nogueira,Vismara, Elena
, p. 995 - 999 (2007/10/02)
New general, selective processes of homolytic alkylation of protonated heteroaromatic bases have been developed using alkyl iodides and t-BuOOH or (t-BuO)2 as sources of alkyl radicals.Both processes are based on the generation of methyl radical from the peroxides, and on iodine abstraction from the alkyl iodide by the methyl radical.The selective processes are the result of combined enthalpic and polar effects.The enthalpic factor governs the equilibrium of iodine abstraction, whereas the polar effect governs the reactivity of the alkyl radicals with the protonated heteroaromatic ring.A redox chain is operative with t-BuOOH and an unusual free-radical chain process is involved with (t-BuO)2.Both chains are particularly effective because of the electron-transfer oxidation of the pyridyl radical intermediate, the ionization potential of which (5.4-6.0 eV) is close to that of lithium (5.39 eV) or sodium (5.14 eV).
