Steric effects in high pressure Knoevenagel reactions
作者:Gérard Jenner
DOI:10.1016/s0040-4039(00)01930-4
日期:2001.1
The pressure effect in Knoevenagel condensations involving ketones and ethyl cyanoacetate is studied. The reactions are diversely affected. For cyclic ketones there is a small effect on the reaction yield. However, in the case of acyclic ketones, the sensitivity of the reaction to pressure increases with increasing steric congestion of the ketone. Such a result highlights the synthetic utility of high pressure for the preparation of hindered functionalized alkenes. (C) 2000 Elsevier Science Ltd. All rights reserved.
Cope; Hofmann; Hardy, Journal of the American Chemical Society, 1941, vol. 63, p. 1855
作者:Cope、Hofmann、Hardy
DOI:——
日期:——
Cope; Hancock, Journal of the American Chemical Society, 1938, vol. 60, p. 2904,2905
作者:Cope、Hancock
DOI:——
日期:——
Daviaud,G. et al., Comptes Rendus des Seances de l'Academie des Sciences, Serie C: Sciences Chimiques, 1971, vol. 272, p. 969 - 972
作者:Daviaud,G. et al.
DOI:——
日期:——
Synthesis of 4-isobutyl substituted thiophenes byGewald reaction
作者:M. G�tschow、H. Schr�ter、G. Kuhnle、K. Eger
DOI:10.1007/bf00813795
日期:1996.3
The Gewald reaction of 4-methyl-2-pentanone with alkyl cyanoacetates was investigated Alkyl 2-amino-4-isobutylthiophene-3-carboxylates (4) were formed, together with bis-(2-amino-3-alkoxycarbonyl-4-isobutyl-5-thienyl)-disulfides (5) and alkyl 2-amino-4-isobutyl-5-morpholinothiophene-3-carboxylates (6). The absence of any 4-methyl substituted aminothiophene in the product mixtures came up highly unexpected. The mechanism of the reaction is discussed with respect to previously reported suggestions.