Abstract An efficient iron-based catalyst system consisting of Fe (BF) 4· 6H 2 O and P (CH 2 CH 2 PPh 2) 3 [tetraphos,(PP 3)] is presented for the highly selective transfer hydrogenation of aromatic, aliphatic, and α, β-unsaturated aldehydes. A wide range of substrates including aldehydes with other reducible functional groups gave the corresponding alcohols in good yields. Formic acid is applied as a cheap, environmentally benign and easy to handle ...