Endo-selective Diels–Alder reaction of methacrylonitrile: application to the synthesis of Georgywood
作者:Andras Borosy、Georg Frater、Urs Müller、Fridtjof Schröder
DOI:10.1016/j.tet.2009.09.089
日期:2009.12
Diels–Alder reactions of alkyl-substituted dienes with acrylonitriles give good yields and endo-selectivities if catalyzed by (organo)aluminum, (organo)boron or gallium halides. The activity of these group IIIa Lewis acids in this reaction correlates with the coordination strength of their nitrile complexes, which deactivate Lewis acids sufficiently, so that the subsequently added diene partner undergoes
如果由(有机)铝,(有机)硼或卤化镓催化,烷基取代的二烯与丙烯腈的Diels-Alder反应可提供良好的产率和内选择性。这些IIIa类路易斯酸在此反应中的活性与其腈络合物的配位强度相关,后者使路易斯酸充分失活,因此随后添加的二烯配偶体进行了Diels-Alder反应,而没有严重的副反应。为此目的,三氯化硼是最有效的催化剂。此方法给出了最好的内切/外切-ratios迄今对这些部件报告和Georgywood的嗅觉矢量的选择性合成施加®。