Transition Metal-Diene Complexes in Organic Synthesis, Part 14.1 Regioselective Iron-Mediated [2+2+1] Cycloadditions of Alkynes and Carbon Monoxide: Synthesis of Substituted Cyclopentadienones - Knölker, Hans-Joachim; Heber, Jochen; Mahler, Charles H (Synlett, 1992)