[kriggy]

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

[Enthalpy]

Hypochlorite to chloramines, then Wurtz?

Err, I fear I've put nonsense, but I just couldn't resist, sorry!

[kriggy]

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

[AWK]

Grignard compound from chloramine + chloramine with catalysis ?

[Enthalpy]

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.

[TheUnassuming]

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.

[kriggy]

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.

[Enthalpy]

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

    ??

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.