[C10H15N]

Hi!

two methyl butene + HCN . What's the result ?

CH3-C=CH-CH3 + HCN  -->  .
       |   
     CH3


Thanks.

[adianadiadi]

I think it is better if we use a base so that a nucleophilic addition will occur.

[C10H15N]

I can't change anything. That's a part of my homework, but I don't know how to add HCN to that alkene ... With HCl i used Markovnikov's rule and it was:

CH3-C=CH-CH3 + HCl  -->  CH3-CCl-CH2-CH3
       |                                    |
     CH3                                 CH3

Now how's the reaction with HCN ?

[Dan]

Attempt the question - what do you think? (See Forum Rules)

You have shown the hydrochlorination reaction with HCl. The corresponding reaction with HCN would be hydrocyanation (google/textbook). Do you think this is feasible with HCN?

[C10H15N]

I'm a newbie in chemistry and i barely speak english (I'm from another country). It would be great if you just show me the result and I'll try to understand it ...

I sow this image on wiki but as I said, i'm too newbie to understand ...




 

[orgopete]

I would have said, "No reaction". However, I can find the hydrocyanation wiki page. I am interested, what is the mechanism of that reaction?

[Dan]

In the absence of a catalyst, I would also say no reaction.

Mechanism of the catalysed reactions depend on the catalyst.

[adianadiadi]

I am really curious now to know why the reaction is not possible without a catalyst?

It is the H+ that acts as electrophile and is is common with HX (X=Cl,Br,I) and HCN. So the reaction should occur with HCN too.

I think HF too fails to react and HCl reacts slowly and requires a catalyst. So only stronger acids are reacting.

What do you say?

[orgopete]

HCN is a weak acid. Too weak to protonate an alkene. (HF is also a weak acid.) None the less, a mineral acid can be used. However, the nitrogen would be the nucleophile in that case. I don't know offhand if HCN is used for this reaction, but if acetonitrile is used an acetamide can be isolated after addition to a carbocation.

[discodermolide]

This is usually done with a metal catalyst, for example nickel. This is the basis for the adiponitrile process of DuPont.
see:
http://en.wikipedia.org/wiki/Hydrocyanation