Silver Nanocluster Redox-Couple-Promoted Nonclassical Electron Transfer: An Efficient Electrochemical Wolff Rearrangement of α-Diazoketones
✍ Scribed by Surendra G. Sudrik; Nirmalya K. Chaki; Vilas B. Chavan; Sambhaji P. Chavan; Subhash P. Chavan; Harikisan R. Sonawane; K. Vijayamohanan
- Book ID
- 101835953
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 110 KB
- Volume
- 12
- Category
- Article
- ISSN
- 0947-6539
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
In this work we report the unique electrocatalytic role of benzoic acid protected silver nanoclusters (Ag~n~, mean core diameter 2.5 nm) in the Wolff rearrangement (Scheme 1) of α‐diazoketones. More specifically, the presence of a Ag~n~^0^/Ag~n~^+^ redox couple facilitates a nonclassical electron‐transfer process, involving chemical reaction(s) interposed between two electron‐transfer steps occurring in opposite directions. Consequently, the net electron transfer between the electron mediator (Ag~n~) and α‐diazoketone is zero. In‐situ UV‐visible studies using pyridine as a nucleophilic probe indicate the participation of α‐ketocarbene/ketene as important reaction intermediates. Controlled potential coulometry of α‐diazoketones using Ag~n~ as the anode results in the formation of Wolff rearranged carboxylic acids in excellent yield, without sacrificing the electrocatalyst.