Lecture Series Practice - Guiding through a mechanism

Let me quickly ________________. So we use an ________________, which protonates the pyridine substrates to the pyridinium.  Uh, less electron rich ________________ are more active in the ________________. So the first effect of this is that you activate. Second, this hydrogen bond gives you a very ________________. So it ________________ the auxiliary with the substrate.
And this more ________________ is now ________________ from the ________________ phase, but ________________ by the substituent, um, on the steric center of the ________________ auxiliary. So the bottom phase of this system can then ________________ the heterogeneous catalyst and ________________ that the heterogeneous catalyst ________________.
So we get very high ________________.  And you're then left with this ________________, and of course an ________________ under suitable conditions can ________________. In this reaction, this happens, uh, right away. You form the ________________ and ________________ the auxiliary, and the ________________ gets ________________ to the final piperidine product.