Sakurai Allylation 

The Sakurai Allylation (also known as the Hosomi-Sakurai Reaction) allows the reaction between allylsilanes with a wide range of aldehydes and ketones in the presence of a Lewis acid to form the corresponding homoallylic alcohols.
General features:
1. Dichloromethane is a common solvent for this reaction, which takes place under nitrogen atmosphere at a temperature range between -78 °C and 25 °C.
2. Common Lewis acids: TiCl4, AlCl3, BF3·OEt2, SnCl4.
3. The reaction is highly regioselective: the electrophile attacking at the C3 terminus of the allylsilane.
4. α,β-unsaturated aldehydes react at the carbonyl group, while α,β-unsaturated ketones may undergo conjugate addition.
5. C1 substituted allylsilanes give the (E)-alkene product, while C3 monosubstituted allysilanes give the syn-diastereomer.
6. Protodesilylation is a common side reaction.
Reaction mechanism:
1. Activation of the carbonyl by the L.A.
2. C-C bond formation generates a silyl-stabilized carbocation.
3. C-C double bond formation after loss of the trimethylsilyl group.
4. Cleavage of the C-Ti bond.
Seminal publication:
1. Hosomi, A., Endo, M., Sakurai, H., Chem. Lett. 1976, 941-942. doi.org/10.124...
2. Hosomi, A., Sakurai, H., Tetrahedron Lett. 1976, 1295-1298. (OPEN ACCESS.) doi.org/10.101...
Additional references:
NROChemistry: nrochemistry.c...