organic chemistry international, v 2012
Volume 2012 (2012), doi:10.1155/2012/289023
Transition Metal Ions as Efficient Catalysts for Facile Ortho-Formylation of Phenols under Vilsmeier–Haack Conditions
1Department of Chemistry, Muffakham Jah College of Engineering and Technology, Mount Pleasant, Banjara Hills, Hyderabad 500034, India
2Department of Chemistry, Osmania University, Hyderabad 500007, India
3National Institute of Pharmaceutical Education and Research (NIPER) Balanagar, Hyderabad 500037, India
Aromatic compounds (phenols), when treated with Vilsmeier Haack (V-H) reagent in the presence of transition metal ions such as Cu(II), Ni(II), Co(II), Cd(II), and Zn(II) under reflux conditions, afforded corresponding ortho-formyl derivatives in good yields. Under normal conditions the metal-ion-free V-H reactions are too sluggish and resulted in poor yields. This protocol provides highly regioselective formylation under a mild and efficient condition with simple workup.