Mild and efficient molybdenum-mediated Pauson-Khand-type reaction.

[reaction: see text] The molybdenum-mediated Pauson-Khand reaction promoted by Mo(CO)3(DMF)3 takes place under very mild conditions in the absence of any promoter. High yields in Pauson-Khand adducts are obtained in the cyclization of a wide variety of functionalized 1,6- and 1,7-enynes. Enynes bearing electron withdrawing groups at the alkene terminus are particularly good substrates.