A novel low-valent titanium (LVT) induced one-pot synthesis of phenanthrenes (25–38% yield) from ortho-alkoxy aromatic aldehydes/ketones was reported by us earlier. Activity of LVT complex could be modulated rationally by using catalytic amount of pyridine. Use of this LVT-pyridine reagent system improved the yields of phenanthrenes (3) by two folds.
S. M. Kadam, Nayak, S. K., and Banerji, A., “Dramatic Influence of Nitrogen Heterocycles on the Activity of Low-Valent Titanium Reagent: An Improved One-Pot Synthesis of Phenanthrenes”, Synthetic communications, vol. 25, pp. 135–142, 1995.