December 25, 2024, 11:07:00 AM
Forum Rules: Read This Before Posting


« previous next »
Pages: [1]   Go Down

Topic: Mechanism for removal of tboc group by tfa  (Read 23684 times)

0 Members and 1 Guest are viewing this topic.

Offline mrsandman

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
Mechanism for removal of tboc group by tfa
« on: February 25, 2009, 07:57:24 PM »
I have a question about deprotecting tboc group with tfa



I'm thinking that the Nitrogen will attack the carbonyl on TFA and form a tetrahedral intermediate.  Then the OH on TFA would be in proximity to the the carbonyl to the amide and that would attack and you would have like a cyclobutane like structure and the lone pairs would come down and in the end you woud have the tboc group attached to the tfa + the deprotected molecule.
Logged

Offline mrsandman

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
Re: Mechanism for removal of tboc group by tfa
« Reply #1 on: February 25, 2009, 11:49:14 PM »
nvm got it
Logged

Offline expert

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +2/-0
Re: Mechanism for removal of tboc group by tfa
« Reply #2 on: February 26, 2009, 12:26:41 AM »
I don't know what you've found. Please share with us. I'm sure TFA protonates carbonyl group in CO(OBu-t) and the positive charge moves to t_Bu group that among alkyls stabilizes the positive charge the best. t_Bu+ cleaved from the molecule and gets quenched by any nucleophile available around, even if it'd CF3COO-. Obviously, CO2 released at the next stage.
Logged

Offline Dynamic

  • Regular Member
  • ***
  • Posts: 17
  • Mole Snacks: +0/-0
Re: Mechanism for removal of tboc group by tfa
« Reply #3 on: February 26, 2009, 08:43:40 PM »
Did you get isobutene as one of your products?
Logged

Offline expert

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +2/-0
Re: Mechanism for removal of tboc group by tfa
« Reply #4 on: February 27, 2009, 01:08:06 AM »
You do, by loosing proton from Me3C+, if no good nucleophiles around.
Logged

Offline ruler9

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-2
Re: Mechanism for removal of tboc group by tfa
« Reply #5 on: November 06, 2009, 08:56:08 PM »
Logged

Offline movies

  • Organic Minion
  • Retired Staff
  • Sr. Member
  • *
  • Posts: 1973
  • Mole Snacks: +222/-21
  • Gender: Male
  • Better living through chemistry!
Re: Mechanism for removal of tboc group by tfa
« Reply #6 on: November 07, 2009, 02:19:17 PM »
Is the nitrogen of an amide the most basic part?  How would that change the mechanism you drew?
Logged
Pages: [1]   Go Up
« previous next »
Sponsored Links