orgo q

[nixon13]

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What does NaNH2 do?

 

[PooyaH]

What does NaNH2 do?

NH2 is a base so it would pull off a Hydrogen! One thing I know is that it could be used in alkylation of alkynes

 

[DRHOYA]

I think it forms an alkyne.

 

[Aceofspades]

It is a general base, but can also be used for nucleophilic aromatic substitution through a benzyme mechanism.

 

[NuckingFutz]

On a somewhat related tangent... is NaOC2H5 considered a strong base? Is OC2H5 a bad leaving group?

 

[PooyaH]

On a somewhat related tangent... is NaOC2H5 considered a strong base? Is OC2H5 a bad leaving group?

NaOC2H5 is a strong base! I'm not sure if it is considered a bad leaving group, but I don't think it's a good leaving group!

 

[doc3232]

NaOC2H5 is a strong base! I'm not sure if it is considered a bad leaving group, but I don't think it's a good leaving group!

OC2H5 is similar to OH- but an even worse leaving group because the C2H5 is electron donating (on top of the negative charge on the Oxygen)...OH- is a bad leaving group...

 

[doc3232]

NaNH2 is basically NH2, which is basically the strongest base, pKa of like 45 or 50, maybe 60...

 

[PooyaH]

OC2H5 is similar to OH- but an even worse leaving group because the C2H5 is electron donating (on top of the negative charge on the Oxygen)...OH- is a bad leaving group...

That's what I thought....thanks

 

[osimsDDS]

NaNH2 is s strong base, check out destroyer ochem road map #5 all the way to the right you have 1,2 dichloro butane...it forms 1-butyne...

 

[drgreen]

OC2H5 is similar to OH- but an even worse leaving group because the C2H5 is electron donating (on top of the negative charge on the Oxygen)...OH- is a bad leaving group...

Straight from wikipedia..... (lability is the ability for a functional group to leave)
In room temperature water, the sequence of lability is:
Less lability
amine NH2−
methoxy CH3O−
hydroxyl HO−
carboxylate CH3COO−
F−
water
Cl−
Br−
I−
azide N3−
thiocyanate SCN−
nitro NO2
Greater Lability

NO3− is also weaker than F−.

 

[klutzy1987]

NaNH2 is a very powerful base that can be used in almost all eliminations. It is a stronger base than even acetlyne anion and therefore can be used to alkylate an alkyne. Dunno if it is a stronger base than a grignard?? i wonder??

 

[jdent]

When ever you see NaNH2 realize that an elimination is taking place and will form a multiple bond. See road maps in destroyer.

 

[futuredent22]

NaNH2 is a very powerful base that can be used in almost all eliminations. It is a stronger base than even acetlyne anion and therefore can be used to alkylate an alkyne. Dunno if it is a stronger base than a grignard?? i wonder??

I doubt its stronger than grignard. An alkane has a pKa of 60, making its conjugate base, the grignard, very very strong.

 

[klutzy1987]

I doubt its stronger than grignard. An alkane has a pKa of 60, making its conjugate base, the grignard, very very strong.

Come to think of it you're right. That is why you can not alkylate an alkane.