In: Chemistry
What are the four factors to consider when deciding whether a reaction proceeds via an SN1 or an SN2 reaction mechanism? How does each factor play a role?
1. substrate:
for sn2 mechanism, the order of substrates are 10 > 20> 30
for sn1 mechanism the reactivity order of substrate is 30 > 20 > 10.
2. nature of leaving group:
conjugate base of weak acid is the good leaving group in sn2 & sn2
3. nature of nucleophile:
strong nucleophiles favors sn2 mechanism
weak / moderate nucleophiles favours sn1 mechanism.
4. solvent
polar protic solvents favours sn1 mechanism
polar aprotic solvents favours sn2 mechanism.