Classical Proton Sponges

T4.5 Start from Section 4.14 Superacids and superbases which covers classical examples of superbases, nitrides, and hydrides of s-block elements. However, there are several groups of superbases that you can look at. For example, amides (diisopropylamide related) are commonly used superbases. More modem are phosphazene bases which are neutral rather bulky compounds containing phosphorus and nitrogen. An interesting topic is a proton sponge (or Alder s base) and its derivatives as well as several theoretical and practical approaches used in rational design of superbases. 

In summary, guanidinophosphazenes belong to the most basic, experimentally determined class of superbases, followed by phosphazenes, proazaphosphatranes and guanidines. Amidines and classical proton sponges generally show less pronounced basicity. 

---