[ilikeanimals12334]

Hi I'm back again.

Anyways, I have a list of reactions to identify which ones halogenoalkes go under:

1) Nucleophilic substitution
2) Electrophilic substitution
3) Elimination
4) Free radical addition
5) hydrophilic addition

I have already managed to identify that they undergo 1 and 3. I also said that they went through 2 but that was wrong when I got my work back. My question is do they only undergo through 1 and 3 and I'm just making crap up or is there a 3rd one, if so can anyone give me guidance because I can't find anything about it.

[ilikeanimals12334]

I think it might be hydrophilic addition because they go through hydrolysis? Or is that two separate things?

[Dan]

Hydrolysis is a substitution reaction. Presumably "hydrophilic addition" means hydration (addition of water).

Consider the structure of a haloalkane: is there any theoretically feasible way in which you can add more atoms to the structure (without losing any)?

[ilikeanimals12334]

Yes I would assume it means addition of water too, I am looking at the structure of a halogenoalke, to me it looks like there isn't a way to add more atoms without substituting or removing any, am I wrong? :S sorry I'm not that bright with chemistry.

[Dan]

I am looking at the structure of a halogenoalke, to me it looks like there isn't a way to add more atoms without substituting or removing any

I agree. Haloalkanes are saturated - you can't add atoms, only substitute or eliminate atoms.

[ilikeanimals12334]

Ok so I would assume that means that 1 and 3 are the only reactions? or would you include 2 aswell? Thanks

[sjb]

I agree. Haloalkanes are saturated - you can't add atoms, only substitute or eliminate atoms.

Dess-Martin periodinane, for instance, or perchlorates?

[Dan]

I agree. Haloalkanes are saturated - you can't add atoms, only substitute or eliminate atoms.

Dess-Martin periodinane, for instance, or perchlorates?

Haha, I wondered if I'd get called out on hypervalent iodine - DMP and iodanes in general did occur to me too, but DMP is an aryl iodane (i.e. not haloalkane-derived). Maybe you can add F₂ to iodoalkanes (to make (difluoroiodo)alkanes - F₂IR), I don't know, but usually organoiodanes are aryl substituted. I thought it was probably beyond the scope of the discussion.

Re: alkylperchlorates, I thought those were made by substitution with a perchlorate salt?

[Babcock_Hall]

IIRC Haloalkanes can undergo further halogenation under free radical conditions, which is one reason that they often not synthetically useful reactions.  However, I would not call such a reaction a free radical addition.

[ilikeanimals12334]

Yeah I wouldn't all it addition either, I knew they underwent it but it's free radical substitution, no?

[Babcock_Hall]

Yes, I would call it a free radical substitution also.