SEARCH Articles Figures Tables 2-Substituted cycloaddition Cycloaddition 3- substitution Cycloaddition nucleophilic Nucleophiles substitution reactions Nucleophilic substitution 3 + 2] cycloaddition Nucleophilic substitution 3 + 4]/ cycloadditions Nucleophilic substitution reactions nucleophiles Substitution reactions nucleophile Substitution reactions nucleophilic