09-09-02 16:15
No 354591
Nickel-on-Charcoal - a revolutionary dirt cheap alternative to Pd as a heterogenous catalyst?
../rhodium/pdf /nickel-on-cha
../rhodium/pdf /nickel-on-cha
(Verbose Viking)
09-09-02 18:21
No 354617
from ../rhodium /index.h
the link to those PDF-files?
Weedar
Me fail English?That's unpossible!
(Chief Bee)
09-09-02 20:48
No 354652
At the bottom of "Miscellaneous".
Not all the PDF documents in the /pdf/ directory are linked, if you didn't know, a few are just linked from posts here at the Hive.
(Master Searcher)
09-10-02 01:03
No 354705
How about this?
http://www.geocities.com/dritte123/Nipat
http://www.geocities.com/dritte123/PSPF.
The hardest thing to explain is the obvious
(Chief Bee)
09-10-02 01:56
No 354715
I really should read your page more often - it contains so much good things. Now, if I just had a little army of clones who could convert your immense list into actual "suggested procedures" - it is really a shame that there are so many unused methods hidden there...
(Hive Addict)
09-10-02 06:27
No 354803
I read both papers, so, does this mean that to do a reductive amination, you need one of the phosphine ligands?
Can this be used straight up for a CTH?
( Some minor example would be useful for us farther down the learning curve...)
Infinite Radiant Light - THKRA
(Chief Bee)
09-10-02 09:23
No 354846
It has not been tried as a CTH substitute - Yet.
The articles only talk about using it for other catalytic reactions where usually Palladium only has been used before, as in Suzuki/Heck couplings with aryl halides.
(Hive Bee)
09-10-02 11:44
No 354857
Ni/Al2O3 and Ni/C is mentioned in some of my books on heterogenous catalysis. But it appears as it is not very widely used. The reason for this can be conservative chemists as well as a very narrow usefulness. For our purposes it does indeed seem quite useful. So it seems like this is something I might have to order and test.
(Official Hive Translator)
09-10-02 17:42
No 354910
Excellent find, Rhodi!
Something big is hiding here; no doubt. Eventually.... Maybee....
Am i correct that there is (as of today) no way to prepare Ni(0) species from Ni(II) other than w/Bu-Li? I mean, pyrolysis is an option too, but the activity of such catalyst yet remains to bee established, no?
Any chances that it could bee used as a Pd substitute in a Wacker? (and - in what way would it bee different in properties from NiCl2, for that matter?)
.....his email adress, that began with labrat@.....
A coincidence, certainly, but a funny one...
Where is this guy nowadays[sigh]....?
Antoncho
(Chief Bee)
09-10-02 22:40
No 354983
NaBH4 most certainly reduce Ni(II) to Ni°, as should a lot of ig-noble metals (like Zn/Al does in the Urushibara catalyst preparation), but as I have read the articles (and especially the second), there is a need to do this only in special circumstances, not as a standard procedure.
(Stranger)
06-21-03 18:25
No 441560
Tried grinding up some nickels, mixed with some HCL acid,then poured that on some charcoal,then dumped sone zinc in till it stopped reacting.Now could this be be used as a reduction agent?
(Hive Addict)
06-22-03 05:07
No 441629
First: No. It canīt be used as a "reduction agent" or catalyst in organic chemistry after my best of knowledge.
Second: Yes. It can be used as a first class agent for reducing complete wrong expectations on how things might work in chemistry.
Also if the papers was followed up to the point it would have given you a weak catalyst which biggest value was to enable some chemists to publish a paper.
Much more active nickel catalyst is prepared by depositing Ni on celite by precipitation. Stoneold. PolySam had it on his page somewhere since ever.
(Stranger)
06-24-03 18:31
No 442201
So none of these posts about different methods preparing nickel catalyst are producing a catalyst that has chance at producing some honey?
(Hive Addict)
06-25-03 04:28
No 442312
Urushibara Ni on Al definately works, it has been proven repeatedly!
Eh? ma faut n'exist pas.
(Stranger)
06-25-03 13:36
No 442420
This calls for the disclosure of some more information!
Urushibara Ni on Al for reducing benzylic aminoalcohols?
Come on!
Temperature ?
amounts/ratios ?
solvent(s) ?
pressure ?
incantations ?
WizardsX was the only one who claimed a working Ni reductionon this. With W6 raney Nickel used in substrate to catalyst ratio far out.
tell tell tell.....
(Chief Bee)
06-25-03 14:55
No 442429
I don't think anyone has used Urushibara for the reduction of your particular benzyl alcohol, and thus you cannot be spoonfed the data.
Just use a huge excess of U-Al-Ni, and run it overnight. If you get no conversion, try it at reflux. If you then get tars, lower the temperature again. If you succeed, then lower the U-Al-Ni ratio as far as you can without losing yield. You need to experiment yourself.
06-25-03 18:28
(Rated as: UTFSE!)
(Stranger)
06-25-03 22:34
No 442517
I had in mind the experimental section of:
../rhodium /fenflur
Where there the authors tried invain to reduce such a compound:
[quote]According to the literature [11], hydrogenation of an alcohol group in benzylic position is easy and is performed in mild conditions (5% Pd/C in alcohol at room temperature and standard pressure). However beta-aminated benzylic alcohols are much harder to hydrogenolyse: the yield is acceptable when the reaction is performed in acidic medium [12-14].
Our experiments, using a mixture of the aminoalcohols 4E + 4T + 11E + 11T and different conditions were not successful: when using mild conditions (ethanol-60°C-24h without activator), the reactants were isolated unchanged, and using harder conditions (acetic acid or water-100-110°C-1 to 16 h-in presence of concentrated hydrochloric and sulfuric acid), gives general degradation. The expected products, the amine 1 and the alcohol 6 could only be detected in trace amounts.[quote]
As it appeared to me that AntibodyII was refering to such a reduction done with U-Al-Ni my interest was caught. (on a second read I am not sure now - if AB would specify the reaction he talks about?)
Rhodium, somebody who has to much time and money may try to do this I prefer routes referenced as successful - they are hard enough to reproduce.
As the benzylic alcohols are easy made by biosynthetic processes subst. and unsubst., stereoselective and in fair yields the reduction of those is a reaction of growing importance but still to be seen as problematic. The catalytic hydrogenation over noble metal catalysts would have been first choice but the results disclosed in the article are depressing. What now? Silanes? The wonderweapon on the hydroxyl group?
(Chief Bee)
06-25-03 23:39
No 442526
A lot of time and money? It really doesn't cost more to perform a dozen such experiments than most people spend on alcoholic beverages on a single evening... And if you skip TV for 1-2 weeks, then you have enough time for the experiments too.
(I'm Yust a Typo)
06-25-03 23:46
No 442529
Cookie time!
"Opportunity is missed by most people because it is dressed in overalls and looks like work."
(Thomas A. Edison)
A Puritan is a person who is unhappy because someone, somewhere, is having a good time
06-26-03 00:50
(Rated as: UTFSE!)
(Chief Bee)
06-26-03 01:13
No 442544
You are in no position to demand any answers from us, especially not when it is your job to UTFSE and easily find the answer yourself.
But because I am so helpful, I will here provide you with reading material about reduction of phenylnitropropenes to amphetamines using Urushibara catalysts (U-Ni-Al) until your bad karma decays enough for you to post again.
Urushibara Style Amphetamine (by Ritter) (../rhodium /amph.u
Synthesis of DOB using Usrushibara Catalyst (by Phikshun2) (../rhodium /dob.ht
(Stranger)
06-26-03 18:27
No 442703
Punished for asking a question?I read what has been posted about Urushibara nickel,even seen pictures of someone running a batch, but still have a few questions.The only question that is bad, is the one that's not asked.
(Chief Bee)
06-27-03 10:42
No 442851
You asked the same question twice in the same thread, in a not too nice tone, and this while the answer is easily found by either using the search engine here or on my site.
(Stranger)
06-27-03 18:56
No 442949
Sorry.
06-27-03 21:15
(Rated as: insignificant)