[orgo814]

I'm being asked to explain why the reaction NH3 + CH3OH2+ yields CH3NH3+ + H2O won't work.
According to my solutions manual, it wouldn't work because the first step would be an acid-base reaction resulting in NH4+ CH3OH. I understand that the NH4+ doesn't have an electron pair and therefore won't be able to react but my QUESTION is this: Why can't the NH3 take the CH3 and the leaving group be H2O (a weak base... which we want).

[discodermolide]

What is CH₃OH₂?

[orgo814]

It's CH3OH2+

I'm not sure I just thought I could take the CH3 and have H2O be a leaving group... but I don't understand why that wouldn't work

[camptzak]

I think because the acid base reaction will happen before the Sn₂ can take place.
so you get ammonium and methanol.

[orgopete]

Proton transfer reactions are faster than substitution reactions. Think about it. A proton is unshielded in any way. A carbon has an inner pair of electrons and surrounded by an additional four pairs of electrons. Those electrons provide a barrier to attack on the carbon compared to a proton.

[Potassiumbubbles]

NH3 + CH3OCH3 -> CH3NH2 + CH3OH

Why this reaction indicated in that will not likely don't occur?

[rolnor]

NH3 + CH3OCH3 -> CH3NH2 + CH3OH

Why this reaction indicated in that will not likely don't occur?

You need the CH3O- to act as leavinggroup, is that likely? Is CH3O- a strong or weak base?