Substitution reaction

Nucleophilic substitution

Medicinal chemistry

Catalysis

Organic chemistry

Nucleophile

Chemistry

Steric effects

Bromide

Alkyl

Azide

Halogen

Electrophile

Bromine

Stereochemistry

SN2 reaction

Science

Attack from the front Biomolecular substitution reactions are widely applied to compounds with carbon-halogen bonds. Typically, an incoming reactive group will attack the carbon from behind its bond with the halogen, causing the halogen to depart in the opposite direction. Zhang et al. now present an asymmetric catalytic substitution reaction that flips the script with an attack on the halogen from the front. Specifically, nitrogen and sulfur nucleophiles stripped bromine from a variety of carbon centers activated by electron-withdrawing groups. A chiral cationic catalyst then directed the carbon fragment back to form a carbon-sulfur or carbon-nitrogen bond enantioselectively. Science , this issue p. 400

An enantioconvergent halogenophilic nucleophilic substitution (S <sub>N</sub> 2X) reaction

An enantioconvergent halogenophilic nucleophilic substitution (S N 2X) reaction

An enantioconvergent halogenophilic nucleophilic substitution (S _N 2X) reaction