Carbonyls

Question 1

What happens when an amide reacts with Grignards, followed by acid work up?

Answer 1

1 equivalent of the grignard will react with the carbonyl, and stabilised via mgbr
Following acid work up, the amine is protonated, and so the hydroxyl kicks down and kicks out the amine
This forms a ketone with an additional alkyl and amine

Question 2

What happens when a nitrile reacts with Grignard’s, followed by acid work up ?

Answer 2

1 equivalent will attack and for an imine
Upon acid work up, water will attack, and end up forming a ketone by kicking out the ammonia (protonation)

Question 3

How can multiple substitutions occur for reductions for amides/nitriles, whilst this cannot occur when using Grignard’s?

Answer 3

Li+/AlH3 can bind to species and enable them to be stabilised/good leaving groups
e.g amides–amines, by kicking out alh3o-R

Grignard’s cannot do this, and instead can only attack once unless there is already a good leaving group present