Asymmetric pinacol coupling of aromatic aldehydes catalyzed by chiral diamines/low valent titanium complexes gave corresponding pinacols in good yields with high diastereoselectivity and moderate enantioselectivities. Asymmetric pinacol coupling of aromatic aldehydes catalyzed by chiral diamines / low valent titanium complexes gave corresponding pinacols in good yields with high diastereoselectivity and moderate enantioselectivities.