What does an iminium intermediate do to the beta carbon?

• It shields it from all attack
• It makes it more electrophilic
• It turns it into a base

An amine condenses with a ketone to give an enamine. Which position is activated?

• The beta carbon as an electrophile
• The alpha carbon as a nucleophile
• The oxygen as a leaving group

After its step, the amine catalyst is released unchanged and can cycle again.

Circle one:   True   False

Turnover is sluggish although binding is fast. What is the likely choke point?

• Release of the catalyst after the step
• Weighing out the starting aldehyde
• Choosing the flask size

A chiral pyrrolidine blocks the top face of its enamine. Where does the partner attack?

• The top face, through the shield
• Neither face, the reaction stops
• The open bottom face

A drug intermediate must contain no metal traces. Which route fits?

• A palladium-catalysed route with extra ligands
• The small-amine organocatalytic route
• A route with two different metals

An aldehyde plus a chiral amine gives racemic product. What does that tell you?

• It shielded neither face
• The aldehyde was too pure
• Water was missing from the flask

A student draws attack on the shielded face and predicts the wrong mirror image. What fixes the prediction?

• React through the open face
• Doubling the catalyst loading
• Heating the mixture harder