[Dan]

Benzaldehyde -> B-Nitrostyrene -> Phenylethylamine -> Tetrahydroisoquinoline

The one thing I'm missing is reagents.

For 1->2 i'm guessing a base and nitromethane
2->3 possible Hydrogen and palladium on a carbon support

These sound good

3->4 I'm not sure

This is a classic named reaction, and is a stepwise combination of two common reactions I'm sure you'll have seen before. I'll give you a hint: You need to add a CH₂ between the N and the Ph groups. What kind of reactivity do amines and alkyl-substituted arenes show - nucleophilic or electrophilic - and what sort of reactions do they participate in? Can you think of any appropriate C sources based on that?

[SpectroKid1]

Benzaldehyde -> B-Nitrostyrene -> Phenylethylamine -> Tetrahydroisoquinoline

The one thing I'm missing is reagents.

For 1->2 i'm guessing a base and nitromethane
2->3 possible Hydrogen and palladium on a carbon support

These sound good

3->4 I'm not sure

This is a classic named reaction, and is a stepwise combination of two common reactions I'm sure you'll have seen before. I'll give you a hint: You need to add a CH₂ between the N and the Ph groups. What kind of reactivity do amines and alkyl-substituted arenes show - nucleophilic or electrophilic - and what sort of reactions do they participate in? Can you think of any appropriate C sources based on that?

I've had look around the web & literature. Is it a Pictet-Spengler reaction? I actually haven't came across this so far in my degree, hence I didn't recognise it. Given it used Aldehydes and acid for the reaction, I'd guess you need HCHO and a general inorganic acid like HCl?

[Dan]

Is it a Pictet-Spengler reaction? I actually haven't came across this so far in my degree, hence I didn't recognise it. Given it used Aldehydes and acid for the reaction, I'd guess you need HCHO and a general inorganic acid like HCl?

Yes exactly. It's essentially an imine formation followed by an intramolecular Friedel-Crafts reaction.