Vala Ruturajsinh M, Patel Divyang M, Sharma Mayank G, Patel Hitendra M
Department of Chemistry, Sardar Patel University Vallabh Vidyanagar-388120 Gujarat India
RSC Adv. 2019 Sep 13;9(49):28886-28893. doi: 10.1039/c9ra05975j. eCollection 2019 Sep 9.
In this study, we successfully explored the effect of steric hindrance on the one-pot reaction of different aryl aldehydes with malononitrile and -substituted 2-cyanoacetamide in the presence of piperidinium acetate as the catalyst. It involved the Knoevenagel condensation of the aldehyde and malononitrile to produce arylidene malononitrile as an intermediate, which was further treated with -substituted 2-cyanoacetamide to give 6-amino-2-pyridone-3,5-dicarbonitrile derivatives when the less steric bulky group was involved. High steric hindrance changed the earlier reaction route and gave -substituted 2-cyanoacrylamides a slower route.
在本研究中，我们成功探究了空间位阻对不同芳醛与丙二腈及α-取代的2-氰基乙酰胺在乙酸哌啶鎓作为催化剂存在下的一锅反应的影响。该反应涉及醛与丙二腈的Knoevenagel缩合反应，生成亚苄基丙二腈作为中间体，当涉及空间位阻较小的基团时，该中间体再与α-取代的2-氰基乙酰胺进一步反应，得到6-氨基-2-吡啶酮-3,5-二腈衍生物。高空间位阻改变了早期的反应路线，使α-取代的2-氰基丙烯酰胺的反应路线变慢。
