Fe<sub>3</sub>O<sub>4</sub> Nanoparticles as an Efficient and Magnetically Recoverable Catalyst for the Synthesis of <font>α</font>,<font>β</font>-Unsaturated Heterocyclic and Cyclic Ketones under Solvent-Free Conditions
作者:Tooba Alishiri、Hossein A. Oskooei、Majid M. Heravi
DOI:10.1080/00397911.2013.786089
日期:2013.12.17
Abstract An efficient and green procedure has been developed for the synthesis of monoarylidenes of cyclic and heterocyclic ketones. The reaction was carried out under solvent-free conditions in the presence of a catalytic amount of nanosized magnetite (Fe3O4). The catalyst was easily removed by using an external magnet. The structures of the products were deduced from their 1H NMR, 13C NMR, and infrared
Phosphoric acid mediated tautomerism of imines: addition of a secondary enamine intermediate to aldehydes
作者:Lindsey O. Davis、Marcella A. Putri、Caitlin L. Meyer、Christopher P. Durant
DOI:10.1016/j.tetlet.2014.04.002
日期:2014.5
A phosphoric acid derivative has been shown to promote the addition between an imine and several aldehyde substrates through an enamine intermediate to give cross-aldol condensation products. The reaction scope and preliminary mechanistic investigations will be presented.
alkylation of the cycloadduct. The Diels–Alder reaction of γ-hydroxybutenolides with dienes gave good yields of cycloadducts under thermal and Lewis acid catalyzed conditions. The application of this methodology to a more complex system was demonstrated by the synthesis of a model system for the tricyclic himbacine core. The stereo- and regioselective Diels–Alder reaction established three of the stereogenic