In the presence of a catalytic amount of RuCl(PPh3)(3), a cross-coupling of 3-buten-2-ol (2) with aldehydes and imines was developed via a tandem olefin migration-aldol-Mannich reaction in bmim[PF6]. With In(OAc)(3) as co-catalyst, alpha-vinylbenzyl alcohol (4) and aldehydes underwent similar coupling reactions. Compared with aqueous and other organic solvents, complementary diastereoselectivity was observed with ionic liquid as the solvent. The ionic liquid/catalyst system could be reused at least five times without loss of activity. (C) 2004 Elsevier B.V. All rights reserved.