Best leaving groups for organic reactions?

Most often encountered leaving groups are halogens (Group17). The larger the atomic radius the better of a leaving group halogen is and therefore, I- > Br-> Cl-

Water and OTs are great leaving groups as well.

Thus, according to the David Klein book here is the list of best to worse leaving groups.

To book a session with an incredible organic chemistry tutor in Washington, DC or online, click here

#organicchemistry