Hypervalent Iodine
While the idea of "hypervalent" iodine compounds may seem a difficult concept at first, the chemistry is easily related to the core concepts of basic organic chemistry.
For example, [hydroxy-(tosyloxy)iodo]benzene (HTIB) or Koser's reagent bascically functions as a highly evolved bromine analog. If you can think of a reaction of elemental bromine with an organic compound, you already know one of the reactions of HTIB!