Iron-Mediated Radical Halo-Nitration of Alkenes

Abstract

Radical halo-nitration of alkenes using iron(III) nitrate nonahydrate and halogen salt has been developed. The present reaction proceeds by radical addition of nitrogen dioxide generated by thermal decomposition of iron(III) nitrate nonahydrate and subsequent trapping of the resultant radical by a halogen atom in the presence of halogen salt. Application of this method to synthesis of nitroalkenes is also described. The practicality of the present method using nontoxic and inexpensive iron reagents has been shown by the application to broad alkenes.

Iron(III)-Mediated Radical Nitration of Bisarylsulfonyl Hydrazones: Synthesis of Bisarylnitromethyl Sulfones

“…2 In addition, Fe(NO 3 ) 3 ·9H 2 O is well-known to produce NO 2 radical on heating; 3,4 however, its application in synthetic chemistry is limited (Scheme 1a). 5 In continuation of our studies on bisarylhydrazones, 6 we report here an Fe(NO 3 ) 3 ·9H 2 Omediated radical nitration of bisarylsulfonyl hydrazones at moderate temperature (Scheme 1b). The broad substrate scope, use of nontoxic iron salt as the nitro source, and the readily accessible aryl aldehydes and arylsulfonyl hydrazides as the substrate precursors are the significant practical features.…”

Mild Nitration of Pyrazolin‐5‐ones by a Combination of Fe(NO3)3 and NaNO2: Discovery of a New Readily Available Class of Fungicides, 4‐Nitropyrazolin‐5‐ones

“…Runs 1–3 showed that Fe(NO 3 ) 3 ⋅ 9H 2 O is an effective reagent for the nitration of pyrazolin‐5‐one 1 a at 60–80 °C, but at room temperature 4‐nitropyrazolin‐5‐one 2 a was obtained in a yield of only 33 % (run 4). Apparently, an elevated temperature was necessary for the decomposition of Fe(NO 3 ) 3 ⋅ 9H 2 O and the release of the active nitrating agent NO 2 . The introduction of NaNO 2 into the reaction allowed the room‐temperature nitration of pyrazolin‐5‐one 1 a in high yields (runs 5–7).…”

“…Both hydrogen‐atom abstraction and addition to double C=C bonds are typical reactions of NO 2 . For nitration reactions mediated by iron(III) nitrate, the NO 2 free radical was previously suggested to be the active nitration agent …”

Radical Carbonitrosation and Recycling of the Waste Gas Nitrogen Monoxide

“…[2] In the field of nitrogencentered radicals, nitrogen dioxide has recently been used for the halonitration of alkenes by Taniguchi et al, [3] and Studer et al [4] reported hydroamination reactions with Naminated dihydropyridines. Among the reagents suitable for trapping radicals at their nitrogen atoms, sulfonyl azides [5] and arenediazonium salts [6] have received most attention over the last decade.…”