Direct asymmetric additions of ArTi(O-i-Pr)3 to aldehydes catalyzed by a titanium catalyst of (R)-H8-BINOL are reported. The reactions proceed instantaneously at room temperature, affording alcohols in ≥90% ee. Importantly, the ArTi(O-i-Pr)3 reagent differentiates the ligand effectiveness in an order of H8-BINOL > BINOL > TADDOL > diol 3 > disulfonamide 2.
