Allyl- and vinylsilanes react with a variety of electrophiles under conditions of nucleophilic catalysis or Lewis acid promotion (often stoichiometric). The primary advantage of using Lewis acids versus fluoride catalysis is site selectivity—fluoride activation tends to generate allyl anions, which can then react at either the α or γ position. Use of Lewis-acid-activated electrophiles leads to reaction at only the γ position of allylsilanes.