[Extracted]

I'd go with the protection idea as well, and try the quench conditions with just the starting material... no n-BuLi.  I think you'll find the amine is exchanging with the D2O.

[JimCronshaw]

Update: The morpholine derivative has...had something happen to it. I'm unsure what that is. In any case, I'm doing the iodine reaction with the morpholine derivative today to see what, if anything, happens.

I'll probably just protect it with a boc group and try again, if the morpholine/iodine reaction goes.

Also got some NIS to give that a whirl.

[discodermolide]

Update: The morpholine derivative has...had something happen to it. I'm unsure what that is. In any case, I'm doing the iodine reaction with the morpholine derivative today to see what, if anything, happens.

I'll probably just protect it with a boc group and try again, if the morpholine/iodine reaction goes.

Also got some NIS to give that a whirl.

You may e better to persilylate it with HMDS, putting on a Boc still leaves a NH.
I still think than NIS will react with the S atom as I said above.

[orgopete]

I agree with the NIS reaction and Discos suggestion that it will react with sulfur. You might just try the organic synthesis prep of iodothiophene which use iodine and a catalyst. The notes did not describe the mechanism, but I think it would go on sulfur and rearrange. You could look up the org syn refs.