Photolysis of 3-phenyl-, 3-methoxy-and 3-hydroxy-pyridazine 1-oxides afforded furans alone, whereas 3-aminopyridazine 1-oxides gave levulinonitriles and 3-cyanopropionaldehydes (11). Mechanism of their formation are discussed.
A novel methodology for the synthesis of indanone derivates has been developed. The palladium-catalyzed annulation reaction of o-bromobenzaldehydes with norbornene derivatives is achieved through extremely concise reaction processes. The indanone skeleton was established directly via C–H activation of the aldehyde group under a mild reaction condition. This method is simple and practical, which simplified
Clay-catalyzed solventless addition reactions of furan with α,β-unsaturated carbonyl compounds
作者:Martín Avalos、Reyes Babiano、JoséL. Bravo、Pedro Cintas、JoséL. Jiménez、Juan C. Palacios
DOI:10.1016/s0040-4039(98)02091-7
日期:1998.12
The reaction of furan with alpha,beta-unsaturated carbonyl dienophiles catalyzed by K10 montmorillonite in the absence of organic solvents produces the corresponding Diels-Alder adducts and, in the case of methyl vinyl ketone, Michael-type products, under much milder conditions than the conventional protocols. The results are consistent with acid catalysis on the clay surface. Acrylates gave lower yields and/or decomposition products. The reaction can be extended to alkynic substrates such as DMAD to afford cycloadducts in good yields. (C) 1998 Elsevier Science Ltd. All rights reserved.
Expeditious ‘On-Water’ Cycloaddition between N-Substituted Maleimides and Furans