Highly enantioselective phenylacetylene additions to ketones catalyzed by (S)-BINOL-Ti complex

The readily available and inexpensive (S)-BINOL ligand in combination with Ti(O(i)Pr)(4) is an effective chiral catalyst for the catalytic asymmetric addition of alkynylzinc to unactivated simple ketones. Good to excellent enantioselectivities were achieved. No previous case has been reported successfully using BINOL to catalyze the addition of phenylacetylene to unactivated ketones, and thus the utility of BINOL in asymmetric catalysis is expanded.