Enantioselective Heck reactions using chiral P,N-ligands

Palladium complexes with chiral phosphinooxazoline ligands are efficient ca talysts far enantioselective Heck reactions with aryl or alkenyl triflates and cyclic olefins. In the arylation and alkenylation of 1,2-dihydrofuran, cyclopentene, 2,3-dihydro-4H-pyran, 4,7-dihydro-1,3-dioxepin, and N-methoxy carbonyl-2,3-dihydropyrrole high yields and good to excellent enantioselect ivities have been obtained. In contrast to palladium-BINAP catalysts, the c atalysts derived from phosphinooxazolines show a very low tendency to promo te isomerization of the product by C-C double bond migration. (C) 1999 Else vier Science S.A. All rights reserved.