Abstract The enantioselectivity of the copper-catalyzed intramolecular cyclopropanation of allyl diazomalonates and the corresponding phenyliodonium ylides was investigated with a series of chiral, non-racemic ligands. The reaction of 6b in the presence of the bis [dihydrooxazole] ligand Xa in refluxing 1, 2-dichloroethane proceeded to 8b with an enantiomer excess (ee) of up to 72% under optimized conditions. In contrast, 8b resulting ...
