12-19-02 22:33
No 390877
This recieved little attention in the serious chem forum, but Sam posted this patent U.S. 3365499.
http://l2.espacenet.com/espacenet/bnsvie
It is worth investigating it involves using solvents like DMF, or DMSO and titrating the mixture with water, instead of alkene to get a higher yeild using the Benzo wacker.
Check it out.
(Chief Bee)
12-19-02 22:46
No 390885
Proper patent linking, see the FAQ: Patent US3365499
(Hive Bee)
12-19-02 23:10
No 390896
Man , look at those ratios!
The best example is number 2
3.6 grams PdCl2 for 16.8 olefin!which would mean 9.55 g for a 100 g batch! Costly!
I guess if we played with the time for reaction, maybe we could use a lot less catalyst!
(Hive Bee)
12-19-02 23:17
No 390902
Like on Rhodiums page there is a similar procedure where DMF is used, and the reation was done this way (but it was not explained in that case why), you'll see you can adjust the ratio of Pd downward. I mentioned in the serious chem forum that the ratios seemed excessive but I think this can be amended by adjusting the addition rate of H20 to coincincide with the reoxidation rate of the lesser amount of Palladium used.
And gabd I think you are right in regards to "i guess if we played with the reaction times"
I think it's just a matter of adjusting addition rates, maybe applying a little heat, and extending reaction times, but it's a very viable modification indeed, and it really makes sense when you think that water does slow the rate of catalyst coordination to alkene, after all DMSO is not hard to find.