Modular strategy for the synthesis of functionalized aryl-fused azabicyclo[2.2.2]octanes via radical-mediated cascade cyclization
作者:Helena C. Malinakova、Sandeep N. Raikar、Lucas F. McCormick
DOI:10.1016/j.tetlet.2014.05.001
日期:2014.7
A two-step synthesis of rare 2-azabicyclo[2.2.2]octanes is described. N-propargyl amides obtained via Cu(I)-catalyzed three-component coupling, underwent radical-mediated cascade cyclization to afford 5,6-aryl-fused 2-azabicyclo[2.2.2]octanes with arylidene functionality on the two-carbon bridge in 43–62% yields. Phenylidene and 1-naphtylidene derivatives were obtained exclusively as Z diastereomers
描述了稀有的2-氮杂双环[2.2.2]辛烷的两步合成。通过Cu(I)催化的三组分偶联获得的N-炔丙基酰胺进行自由基介导的级联环化反应,从而在二碳桥上得到具有亚芳基官能团的5,6-芳基稠合的2-氮杂双环[2.2.2]辛烷收率为43-62%。亚苯基和1-萘基衍生物仅作为Z非对映异构体获得,而亚芳基取代基中的富电子基团提供了以2.3∶1M的比例有利于Z非对映异构体的产物混合物。