November 28, 2024, 07:56:46 AM
Forum Rules: Read This Before Posting


« previous next »
Pages: [1]   Go Down

Topic: Doing steric demanding Ullmann or Suzuki coupling  (Read 2646 times)

0 Members and 1 Guest are viewing this topic.

Offline kamiyu

  • Full Member
  • ****
  • Posts: 181
  • Mole Snacks: +8/-7
  • Gender: Male
Doing steric demanding Ullmann or Suzuki coupling
« on: October 27, 2014, 10:56:59 AM »
Is there anyone here with experience of Suzuki (or Ullmann) coupling with sterically hindered substrates?

I am doing coupling between carbazole and 9-bromoanthracene

What is the most important factor to boost the yield of such reaction???

Thanks
Logged

Offline C-hemCards

  • Regular Member
  • ***
  • Posts: 25
  • Mole Snacks: +4/-2
    • ChemCards on Amazon
Re: Doing steric demanding Ullmann or Suzuki coupling
« Reply #1 on: October 27, 2014, 10:06:57 PM »
Draw and think about each intermediate, including the ligand on the metal. Then, ask yourself how to minimize the energy required to proceed through each step of the mechanism.
Logged
Learn organic chemistry fast. PM us for a 15% discount code: http://amzn.com/B00NRB5LSA

Offline BobfromNC

  • Regular Member
  • ***
  • Posts: 87
  • Mole Snacks: +14/-1
Re: Doing steric demanding Ullmann or Suzuki coupling
« Reply #2 on: October 30, 2014, 02:21:32 PM »
Try a microwave reaction tube - ie, higher temperatures and pressure. 

Go to hottest reagent possible, iodide or triflate rather than bromide.

If that fails, try heating even more.   But keep it air free, any oxygen will kill you as you go up in temp. 
Logged
Pages: [1]   Go Up
« previous next »
Sponsored Links