18503-44-1Relevant academic research and scientific papers
HYDROXYLAMINE-O-SULPHONIC ACID-INDUCED SUBSTITUTION OF HETEROAROMATIC BASES BY α-OXYALKYL RADICALS FROM ALKYL ETHERS
Citterio, Attilio,Casucci, Domenico,Gentile, Anna,Serravalle, Marco,Ventura, Susanna
, p. 319 - 324 (2007/10/02)
Thermal and Fe(II)-catalyzed decomposition of hydroxylamine-O-sulphonic acid (HOSA) in the presence of alkyl ethers and protonated heteroaromatic bases affords α-alkylation products of the base with high selectivity and yield.The reaction is a radical redox-chain process involving the formation of ammoniumyl radicals ( NH3(+.)), preferential hydrogen abstraction from α C-H bonds of ethers by NH3(+.), trapping of the nucleophilic alkyl radical produced by the base and oxidation of the pyridinyl radical adduct by HOSA or Fe(III).Thermal initiation appears to be somewhat less efficient than Fe(II) or Fe(III) initiation.The α-oxyalkylation process appears to be strongly affected by the reducing properties of the carbon free radicals, their reversibility in the addition to the base and by hydrolysis of HOSA.The selectivity of the hydrogen atom abstraction by NH3(+.) and the competition of the free radical intermediates between addition to the base and oxidation by Fe(III) have been investigated.
