Chemistry - Organic Chemistry - Reactions - Substitution reactions (SN1 and SN2) - SN1 and SN2 Decision Guide

4-step comparison. Step 1: 'SN2 MECHANISM: Bimolecular nucleophilic substitution. One step: Nu attacks as LG leaves. Rate = k[R-X][Nu⁻]. Inversion of stereochemistry. Best with: CH₃-X and 1°-X (unhindered), strong nucleophiles (OH⁻, CN⁻, I⁻), polar aprotic solvents (DMSO, acetone).' Step 2: 'SN1 MEC