Direct Metal-Free Entry to Aminocyclobutenes or Aminocyclobutenols from Ynamides: Synthetic Applications
作者:Benito Alcaide、Pedro Almendros、Carlos Lázaro-Milla
DOI:10.1002/chem.201601044
日期:2016.6.20
The [2+2] cycloaddition of ynamides with the highly polarized reagent Tf2C=CH2 has been developed to regioselectively afford bis(triflyl)aminocyclobutenes in the absence of catalyst under mild conditions. Incidentally, with the ynamides bearing electron‐rich aromatic rings at the C‐terminal, an interesting reactivity switch was observed; a cyclization/hydroxylation sequence yielded 2‐amino‐3‐(trif
酰胺与高极化试剂Tf 2 C = CH 2的[2 + 2]环加成已开发出在温和条件下在不存在催化剂的情况下区域选择性地提供双(三氟乙)氨基环丁烯的方法。顺便说一下,对于在C端带有富电子芳族环的炔基,观察到一个有趣的反应性开关。一个环化/羟基化序列产生2-氨基-3-(triflyl)环丁-2-烯醇。加有醇的氨基环丁烯结构导致通过环化/加氢烷氧基化过程形成氨基环丁烯基醚。此外,通过4个π电子环的制备α-氨基-β,γ-不饱和酮和3-(三氟乙烯)丁a-1,3-二烯-2-胺,证明了官能化的氨基环丁烯作为进一步精细加工的前体的效用。开环。