Aldehyde allylation with allylboronates providing alpha-addition products

Zn(OH)(2)-catalyzed allylation reactions of allylboronates with aldehydes proceeded smoothly in aqueous media; when alpha-substituted allylboronates were employed, the a-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.