Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: xshadow on August 26, 2019, 04:45:17 PM
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HI
:)
I don't understand too much the silyl enol ether formation
Why if I have an Enolate + TMSC (CH3SiCl) the enolate attacks the Si using his O -electrons
I usually have seen an enolate - acting as a nucleophile- attacking an electrophilic atom (like C=O
) with the C carbon atom of enolate...the bond is created between the nucleophilic carbon of an enolate and the electrophilic atom , for example a C- carbonyl
Now here I have that the nucleohilic enolate bond with Si of TMSC through the O-enolates atom ...and NOT the C-enolates atom
Why??!
Thanksss so much :)
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The silylhalide is a hard electrophile and reacts with the hard nucleophile oxygen. The enolate carbon is a soft electrophile.
Here is a link with nice info about this topic:
https://youtu.be/04NYWxuD6d4
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Saw the video but I have some doubt about hard and soft
For example:
PH3 vs NH3 ....I think that PH3 is a softer base/nucleophile than NH3 because the donor atom,P,is larger than N
N3- vs NH2-
Here I don't understand which one is softer ...
Some help? N is the donor atom and in both I have a negative charge
Thankss!
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I think the video is about giving you a generall idea about the concept, not quantifying exactly the nucleophiles being softer or harder.