Hi...I have a doubt:
I know that RLi( normal butyl lithium) and RMgX are strong bases and also strong nucluophiles
Now If I have some acidic hydrogen usually they act as a base and they deprotonate it
the -OH of a carboxylic acid RCOOH(pka≈ 4.75) (and not gives nucleophilic substitutio)
the -NH2 group of an Amide RCONH2 (pka ≈25) (and not gives nucleophilic substitution!)
the -OH of a alcohol or also..water!!
Now if I have an aldehyde or a ketone why I'll get, as major product ,the nucleophilic addition product!?
In ketone and aldehyde I have H-acid(pka ≈20), in the alpha position
So why, here ,does the nucleophilic nature of organometallic compounds prevail over the basic one?
In amides or alcohols I have the deprotonation(over the nucleophilic attack) with an acidic hydrogen having a pka of about 15/25
Ketones have a SIMILAR acidity of alpha hydrogen but my textbook (and also looking online) says that grignard and RLi compounds usually give a nucleophilic attaco on the carbonyl