The Sakurai reaction (also known as the Hosomi–Sakurai reaction) is the chemical reaction of carbon electrophiles (such as a ketone shown here) with allyltrimethylsilane catalyzed by strong Lewis acids.
Lewis acid activation is essential for complete reaction. Strong Lewis acids such as titanium tetrachloride, boron trifluoride, tin tetrachloride, and AlCl(Et)2 are all effective in promoting the Hosomi reaction. The reaction is a type of electrophilic allyl shift with formation of an intermediate beta-silyl carbocation. Driving force is the stabilization of said carbocation by the beta-silicon effect.