Synthetic reactions using organometallics in water. Aldol and allylation reactions catalyzed by Lewis acid-surfactant-combined catalysts/Bronsted acids systems

Aldol reactions of aldehydes with silyl enolates and allylation reactions w ith tetraallyltin have been successfully carried out using Lewis acid-surfa ctant-combined catalysts/Bronsted acids systems. Remarkable enhancement of reactivity by a Bronsted acid such as HCl was observed in these reactions i n the presence of a Lewis acid-surfactant-combined catalyst such as scandiu m tris(dodecyl sulfate) or scandium trisdodecanesulfonate in water. The add ition of Bronsted acids was also effective for catalytic asymmetric aldol r eactions in water using copper bis(dodecyl sulfate) and a chiral bis(oxazol ine) ligand. (C) 1999 Elsevier Science S.A. All rights reserved.