Symmetric and unsymmetric 3,3′-linked bispyrroles via ring-enlargement reactions of furan-derived donor–acceptor cyclopropanes
作者:Johannes Kaschel、Tobias F. Schneider、Daniel Kratzert、Dietmar Stalke、Daniel B. Werz
DOI:10.1039/c3ob40228b
日期:——
A short and concise sequence for the synthesis of symmetrically and unsymmetrically substituted 3,3′-linked bispyrroles is described. Furan as a starting material is subjected to a twofold cyclopropanation by a diazo ester. Conversion of the ester functionalities to the respective ketones is achieved via Weinreb amide formation and the attack of a Grignard reagent. In the presence of amines the ketone
Donor–acceptor cyclopropanes with Lawesson's and Woollins' reagents: formation of bisthiophenes and unprecedented cage-like molecules
作者:Johannes Kaschel、Christian D. Schmidt、Mark Mumby、Daniel Kratzert、Dietmar Stalke、Daniel B. Werz
DOI:10.1039/c2cc37631h
日期:——
Furan-derived donorâacceptor-substituted cyclopropanes were reacted with Lawesson's reagent. Depending on the reaction conditions either bisthiophenes or unprecedented cage-like molecules were obtained. Woollins' reagent always led to the respective selenium-containing cage-like compounds.
Domino Reactions of Donor-Acceptor-Substituted Cyclopropanes for the Synthesis of 3,3′-Linked Oligopyrroles and Pyrrolo[3,2-<i>e</i>]indoles
作者:Johannes Kaschel、Tobias F. Schneider、Daniel Kratzert、Dietmar Stalke、Daniel B. Werz
DOI:10.1002/anie.201205880
日期:2012.10.29
Multiple displacement of oxygen: Electron‐rich oligopyrroles and pyrrolo[3,2‐e]indoles are generated by a domino process induced by donor–acceptor‐substituted cyclopropanes. Up to seven molecules of water are eliminated, thus allowing the introduction of nitrogen and aromaticity.
氧气的多次置换:富电子的低吡咯和吡咯并[3,2- e ]吲哚是由供体-受体取代的环丙烷诱导的多米诺过程生成的。消除了多达七个分子的水,从而引入了氮和芳香性。