August 09, 2020, 01:31:53 PM
Forum Rules: Read This Before Posting


Topic: Ferrocene lithiation and tributhyltin ferrocene  (Read 4088 times)

0 Members and 1 Guest are viewing this topic.

Offline Altered State

  • Full Member
  • ****
  • Posts: 270
  • Mole Snacks: +24/-4
  • Gender: Male
    • Chemistry Hall
Ferrocene lithiation and tributhyltin ferrocene
« on: February 14, 2015, 09:58:46 AM »
I'm currently studying ferrocene metal-derivatives reactivity, but my limiting step is being always first metalathion process of ferrocene.
I tried to reproduce several conditions but with no success -always get products, but low yields-. In many papers is stated that the results are "sometimes not reproducible".

Do you know any reliable, recent procedure to perform a succesful lithiation of ferrocene and subsequent transmetallation?
My goal now is to get tributhyltin ferrocene in a decent yield. Any one knows of a procedure? The only ones I've found are really some old ones.

Offline opsomath

  • Chemist
  • Full Member
  • *
  • Posts: 470
  • Mole Snacks: +50/-8
Re: Ferrocene lithiation and tributhyltin ferrocene
« Reply #1 on: February 16, 2015, 04:34:58 PM »
I struggled with this procedure in grad school - never got a decent yield either. My go-to for monoderivatives of ferrocene is to acetylate then do normal carbonyl reactions to acetylferrocene. Vinylferrocene is easy to make from it. I know this doesn't directly help you - I'm posting in this thread because I'd be interested in any reliable procedure for making mono-derivatives of Fc - slight threadjack.

The one we use for acetylferrocene and vinylferrocene is from Synthetic Pages: http://cssp.chemspider.com/Article.aspx?id=759

Offline BobfromNC

  • Regular Member
  • ***
  • Posts: 74
  • Mole Snacks: +10/-1
Re: Ferrocene lithiation and tributhyltin ferrocene
« Reply #2 on: February 18, 2015, 03:08:35 PM »
I would try using nBuLi and tetramethylethylene diamine as a chelation assister.   That has worked for me in the past on ferrocene compounds.

Offline Altered State

  • Full Member
  • ****
  • Posts: 270
  • Mole Snacks: +24/-4
  • Gender: Male
    • Chemistry Hall
Re: Ferrocene lithiation and tributhyltin ferrocene
« Reply #3 on: February 18, 2015, 04:31:27 PM »
I would try using nBuLi and tetramethylethylene diamine as a chelation assister.   That has worked for me in the past on ferrocene compounds.

That yields the dilithiated product, my goal is the monomotalathion... I only was able to get this product with tBuLi 0ºC or tBuLi + tBuOK at low temperature.

Offline BobfromNC

  • Regular Member
  • ***
  • Posts: 74
  • Mole Snacks: +10/-1
Re: Ferrocene lithiation and tributhyltin ferrocene
« Reply #4 on: March 24, 2015, 04:59:54 PM »
Then I would try 1.1 eq of nBuLi, in THF, added cold, but then warm the solution up to RT before the next step, to ensure complete deprotonation, then re-cool it before the next step.   That should provide the monoadduct.   Look at the Japanese authored (Hayshi?) papers from the 1970-1980's for the best preps.  Don't have my refs here.

Offline NanoTT

  • Very New Member
  • *
  • Posts: 1
  • Mole Snacks: +0/-0
Re: Ferrocene lithiation and tributhyltin ferrocene
« Reply #5 on: July 18, 2015, 09:13:47 AM »
Exclusive preparation of monolithioferrocene actually posed quite a challange for some time, and a good comparison of conditions can be found in a 1996 paper from Sanders and Mueller-Westerhoff - "The lithiation of ferrocene and ruthenocene: a retraction and an improvement".

http://www.sciencedirect.com/science/article/pii/0022328X9505914B

From personal experience I would recommend the tBuLi-KOtBu system. Dropwise addition of tBuLi to ferrocene and KOtBu in THF at -78°C with rapid stirring (minimizing local heating), followed by stirring for 2 h can form monolithioferrocene in >90%. Then you can add your electrophile (portionwise). Raising the temperature, rapid addition of BuLi or too slow a stir rate increases the proportion of dilithioferrocene formed. For a recent example of this approach applied to halogenated ferrocenes, see the link below.

http://pubs.rsc.org/en/Content/ArticleLanding/2013/DT/c2dt32779a

To generate tributyltin ferrocene, an appropriate reagent would seem to be tributyltinchloride (link below)? This paper also has some good discussion on the effects of changing reaction conditions.

http://pubs.acs.org/doi/abs/10.1021/jo00113a033

Hope that helps!

Sponsored Links