New and Efficient Synthesis of Pyrrolo[3,2-<i>b</i>]pyrrole-2,5-diones by Double-Anion-Capture Reactions of Ester Carbanions with Bis(imidoyl)chlorides of Oxalic Acid
作者:Peter Langer、Jörg Wuckelt、Manfred Döring
DOI:10.1021/jo991377u
日期:2000.2.1
A variety of pyrrolo[3,2-b]pyrrole-2,5-diones were efficiently prepared by a new domino-reaction of ester carbanions with oxalic acid−bis(imidoyl)chlorides. This reaction proceeded by condensation of 2 equiv of the ester with the bis(imidoyl)chloride and subsequent intramolecular attack of the nitrogen atoms of the bis-enamine intermediate onto the ester groups. The products, which can be regarded