Intermolecular asymmetric Heck reactions with 2,2-diethyl-2,3-dihydrofuran

Palladium-catalysed intermolecular asymmetric Heck reactions were performed on 2,2-diethyl-2,3-dihydrofuran using chiral diphosphine and phosphinamine ligands. The steric effect of increased bulk at the 2-position was examined for phenylations and cyclohexenylations and lower chemical yields, but similar enantioselectivities were obtained compared to the 2,2-dimethyl analogue. The optimum ee for phenylation was 94% and for cyclohexenylation was 93%, both obtained with the t-Bu-substituted diphenylphosphinoaryloxazoline ligand.