On the direct reduction of arsonic acids to arsenoso compounds: mechanisms and preparations

✍ Scribed by Panayiotis V. Ioannou

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 116 KB
• Volume: 14
• Category: Article
• ISSN: 0268-2605
• DOI: 10.1002/(sici)1099-0739(200005)14:5<261::aid-aoc991>3.0.co;2-7

✦ Synopsis

By using a variety of reducing agents, either alone or in the presence of iodide as a catalyst, the reduction of arsonic acids to arsenoso compounds and/or arsonous acids has been studied. The solvent and temperature are important for a clean reduction. The mechanism of the reduction involves prior protonation of the -AsO 3 H 2 group, and can be rationalized in the framework of the 'hard and soft acids and bases' principle, which is used to predict other reducing systems and to explain other literature data. For preparative purposes, triphenylphosphine/ iodine, hexamethylphosphorous triamide/iodine and ascorbic acid/iodine give flexibility of choice depending on the substrate. The first two of these systems decompose arsonic acids with a weak C-As bond but the last system is sufficiently mild towards the same arsonic acids.