Zn(OH)2-catalyzed allylation reactions of allylboronates with aldehydes proceeded smoothly in aqueous media; when α-substituted allylboronates were employed, the α-addition products were obtained exclusively, and syn-adducts were formed selectively in most cases; the use of Zn(OH)2 with dmp (ligand) in aqueous media is the key to these reactions.
