[viet]

I think the Ph is the benzene.

[discodermolide]

I think the Ph is the benzene.

This is a simple imine formation, acid catalysed, benzene is the solvent and plays no other role.

[viet]

Ok thanks. Would a Ph-Li or Ph-MgBr attack the imine to form the product?

[Doc Oc]

The Ph in the final product has to come from somewhere, and you're right that it likely comes from the benzene solvent.  Your reaction stops one step too early (the iminium), this is a classical named reaction (hint: Gilbert Stork).  If you draw the actual final intermediate you might get an idea of how to finish the reaction.

[ooosh]

I think the Ph comes from the solvent benzene.first is the formation of imine ,second is F-C alkylation, benzene attacks the carbocation of imine.