Cycloaddition reactions of nitrosoalkenes, azoalkenes and nitrile oxides mediated by hydrotalcite
作者:Americo Lemos、João Paulo Lourenço
DOI:10.3998/ark.5550190.0011.515
日期:——
Mg:Al 3:1 hydrotalcite (Ht), used in catalytic quantities, promotes the generation of nitrosoalkenes, azoalkenes and nitrile oxides. These can be intercepted in situ by heterocycles and olefins in [4+2] and [3+2] cycloadditionreactions, producing dihydro-1,2-oxazines, tetrahydropyridazines and isoxazolines. The regeneration and reuse of Ht without loss of activity and the absence of organic solvent
Several improvements in the cycloaddition of carboethoxyformonitrile oxide (CEFNO) with different alkenes are observed in the ionic liquids [bmim][BF4] and [bmim][PF6]. The possibility of obtaining good yields of the corresponding isoxazolines opens the way towards parallel collections of glutamic acid (Glu) analogues. (C) 2003 Elsevier Science Ltd. All rights reserved.
Oremus, Vladimir; Fisera, L'ubor; Timpe, Hans-Joachim, Collection of Czechoslovak Chemical Communications, 1987, vol. 52, # 12, p. 2953 - 2960