Regio- and Diastereoselective Synthesis of N-Aryl-5-alkylidene-5H-pyrrol-2-ones by a new Domino Reaction of 1,3-Dicarbonyl Dianions with Oxalic Acid-bis(imidoyl)chlorides - Langer, Peter; Döring, Manfred (Synlett, 2001)