Question

Can someone please list the ideal circumstances (type of nucleophile, solvent, est) for E1, E2, Sn1 and SN2 reactions? And explain what makes a strong nucleophile vs a weak one, how do you identify them?

Answer 1

Ans. For SN1 and E1 reaction, there is first formation of carbocation takes place that is a slow step and rate determing step. If we have strong nucleophile then it leads to SN1 reaction and If we a good base then we get E1 elimination product.SN1 reaction are favoured in protic solvent.

For SN2 and E2 reaction, it follows concerted mechanism and favours in aprotic solvent. If we have a strong nucleophile then we get SN2 product and if we have a strong base then we get E2 elimination product.

Criteria for strong nucleophile

There must be lone pair on atom for becoming nucleophile and for stronger nucleophile, the lone pairs should not be strongly attached to the atom.

and weak nucleophile are having those lone pairs are tightly attached to the atom.

for eg. CH3CH2O- is a stronger nucleophile than CH3CH2OH