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Electrochemical olefin to ketone -Wacker type
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Author Topic: Electrochemical olefin to ketone -Wacker type
CHEM GUY
Member posted 10-27-1999 07:32 PM
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I know that some one already listed this same topic a while ago but I found some more goodies and insights to a better route. One that is more OTC. First I quote the orginal article.
From "Chemistry Letters", page 121-124, yr 1994
"Table 2 Electrochemical Wacker Process with a Combination of Pd(OAc)2 or PdCl2 and (4-BrC6H4)3N in a Divided or an Undivided Cell a)
Substrate / Products / Yeilds- divided / Yeild undivided
[Safrole] / MDP2P / 57 / 85
...
a) Reaction carried out by useing substrates 1 (1 mmol) and Pd(OAc)2 (divided) or PdCl2 (Undivided) (0.05 mmol) in an MeCN-H2O (7:1)-0.5 M Et4NOTs-(Pt)-(Pt) system at room tempapture for 2.0-3.0 F/mol of electricity.
"
"Table 1. Electrochemical Wacker Oxidation of 1-Undecene (1a) with Organic Mediators a)
Organic Mediator / Products Yeild [ of methyl ketone]
(Br-C6H4)3N / 39
...
HO-C6H4-OH / 27
a) Reaction carried out in a CH3CN/H2O (9:1 V/V, 10 mL)-Et4NOTs-(Pt)-(Pt) system in the presence of Pd(OAc)2 (5 mol %) and an organic mediator (20 mol%) at room tempature (20 C) in a divided cell. Conditions: 3.0 V (0.4-5.5 mA); Electricity charged: 2.5 -3.0 F/mol."
I found this article: Journal of Applied Electrochemistry, 14, yr 1984, page 779-790
It uses iron chloride as the recycler of PdCl and uses an aqueous medium, with no organic co-solvent. Really quickly the article states that the reaction works well with an FeCl3 concentration at and below .5 mol per liter at 35 C, and with .3 mol HClO4- (510 mA per gram Pd and above). It states later, "Presumably, dilute sulfuric acid could replace the perchloroc acid used in this study."
Also the oil and the electrolyte solution are not miscilble nor is the ketone in this study, so they study the dispersing methods and their efficiencies as well. In short the finer the emulsion the better the effeciency and reaction rate.
Higher the tempature the higher the oxidation rate as well.'
In short the wacker oxidation of a safrole like compound could take place in a dilute sulfuric acid electro-cell, with PdCl2
What do you think?
quote: This is true for all wackiness ehh? Its why everyone was shaking the heck outta their 2liter bottles last year. So I'm wondering how to shake shake shake while you're wired for electricity. Acetonitrile fumes are, um, not good. Contact Us | the Hive Powered by: Ultimate Bulletin Board, Version 5.39a
ChemHack
Member posted 10-28-1999 08:59 PM
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"the finer the emulsion the better the effeciency and reaction rate."
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Osmium
Member posted 10-29-1999 03:33 AM
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No. Here the solvent is water, in which the organic molecules won't dissolve. In the SRV the solvent used is an alcohol, and all the ingredients are fully soluble in it.
The shaking is done to help the oxygen dissolve as fast as it is consumed by the reaction.
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