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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: kriggy on November 29, 2018, 03:56:14 PM

Title: formation of N-N bond via oxidation
Post by: kriggy on November 29, 2018, 03:56:14 PM
Hey guys,
im brainstorming a bit about a way how to make a dimer via N-N formation via oxidation. I know hydrazine is made this way but is this method more videly aplicable? To be more specific, I would like to make a benzimidazole dimer that is joined via the N-N bond.

I think I could make it via step by step cyclization approach but since I have the benzimidazole in lab it seems the easiest method to try
Title: Re: formation of N-N bond via oxidation
Post by: Enthalpy on November 30, 2018, 07:19:10 AM
Hypochlorite to chloramines, then Wurtz?

Err, I fear I've put nonsense, but I just couldn't resist, sorry!
Title: Re: formation of N-N bond via oxidation
Post by: kriggy on November 30, 2018, 11:51:25 AM
Haha thats what I was thinking but I cant find much info about those kind of reactions being applied on something else than ammonia -> hydrazine
Title: Re: formation of N-N bond via oxidation
Post by: AWK on December 01, 2018, 12:06:10 PM
Grignard compound from chloramine + chloramine with catalysis ?
Title: Re: formation of N-N bond via oxidation
Post by: Enthalpy on December 19, 2018, 05:30:15 PM
And, are there already good news?

Anders Hoveland made many syntheses with unsaturated azo rings before entering the university, but he hasn't been active here for a while. Maybe you can find him on the Web, he had a website.
Title: Re: formation of N-N bond via oxidation
Post by: TheUnassuming on December 20, 2018, 01:42:02 PM
Apologies, been a while since I've dropped by so missed this thread when it was active. 

If you are still working on this, you might check out work by Stahl (DOI: 10.1021/jacs.8b05245)  and Baran (DOI: 10.1021/ja5013323) labs in this area.  If it will work with benzimidazoles though... who knows.
Title: Re: formation of N-N bond via oxidation
Post by: kriggy on December 21, 2018, 06:05:36 AM
Thanks for the papers, both are quite interesting. Im no longer on this though Im on one project now and we will be starting another one soon I think and this was just an random idea. I looked into the literature a bit and found some papers about the N-N linked benzimidazoles and they (and the intermediates) are bit unstable.

The Stahl procedure looks like something I could try just for fun to see if it works if I can find the correct Cu source.
Title: Re: formation of N-N bond via oxidation
Post by: Enthalpy on December 21, 2018, 07:57:21 AM
In Stahl (DOI: 10.1021/jacs.8b05245) (I access only the abstract) I don't grasp where the hydrogen shall come from to split the N-N bond

c1ccccc1Nc2ccccc2  ::equil::  c1ccccc1N(c2ccccc2)N(c3ccccc3)c4ccccc4 ??

The 1atm O2 supposedly serves to consume the hydrogen atoms weakly bonded to N and provoke the N-N bonding.

Once this hydrogen is bonded to oxygen, I imagine it is irreversibly unavailable.

Do I misunderstand something?

Or could it possibly be instead that the still unbonded carbazole displaces a diphenylamine from the N-N compound, gives it a hydrogen and creates the cross-coupled N-N compound? At least the curve of species concentration versus time supports this scenario.