Highly Efficient Hosomi-Sakurai Reaction of Aromatic Aldehydes Catalyzed by Montmorillonite Doped with Simple Bismuth(III) Salts. Batch and Continuous Flow Studies.

dMontmorillonite doped with simple bismuth(III) salts was found to be an efficient catalyst for the Hosomi-Sakurai allylation of aldehydes. The reaction was performed on different substituted aromatic aldehydes with allyl and methallyl trimethylsilanes. In contrast with most existing methods typically leading to alcohols with the loss of the silyl group, or to mixtures of free and silylated alcohols, our catalytic system delivered selectively in mild conditions and 71-96% yields the corresponding protected alcohols which could be further used in a larger synthetic scheme. The reaction was easily transferred in continuous flow with maintained efficiency and superior scalability.