Good Leaving Groups are Weak Bases C-LG bond is broken during RDS Quality of leaving groups is crucial Sulfonates are excellent leaving groups O CH: CH3SO- 0 tosylate mesylate TsO- MsO- Good Leaving Groups are Weak Bases TsO- MsO￾mesylate C LG bond is broken during RDS Sulfonates are excellent leaving groups O O CH3 SO tosylate CH3 SO O O Quality of leaving groups is crucial