Sciencemadness Discussion Board

Thiol vs. alcohol as a nucleophile

edwardx - 9-11-2014 at 13:08

Since alcohols are stronger bases than thiols, you would expect alcohols to be better nucleophiles in substitution and elimination reaction than thiols! But because sulfur is larger than oxygen it is less solvated by a protic solvent, and because it is more polarizable, it is actually a better nucleophile(in protic solvents). My question is: Are thiols still better nucleophiles in aprotic solvent? Or does the lesser solvation of alcohols in aprotic solvents, cause the more electronegative alcohol to be the better nucleophile?

Chemosynthesis - 9-11-2014 at 15:06

This should be posted in Beginnings.

Size and polarizability are the primary determinants of nucleophilicity in protic solvents. Basicity/electronegativity is the primary determinant in aprotic solvents.

CuReUS - 10-11-2014 at 04:45

you can see this video ,it is very helpful

https://www.khanacademy.org/science/organic-chemistry/substi...