Asymmetric addition of phenylacetylene to aromatic ketones catalyzed by zinc or titanium complexes with chiral hydroxysulfonamide.Chirality. 2009 Apr; 21(4):473-9.C
Various new chiral hydroxysulfonamide ligands (3a-3n, 4a-4d) were prepared. Compounds 3a, 3g, 3i, 3k-3n, 4a-4d could accelerate the reaction and reduce reaction time, and 3a, 3g, 3i, 3k-3n catalyzed the reaction without titanium. The results obtained were promising in terms of yields and enantiomeric excesses (3k up to 85% ee, 4a up to 83% ee).