Gold(I)-catalyzed Cycloisomerization of the Mixed N,S-acetals Generated from Homopropargylic Amines; Mechanistic Implication for the Formal Alkyne Prins Reaction
作者:Cheol-Jae Kim、Won-Taeck Lim、Young-Ho Rhee
DOI:10.5012/bkcs.2010.31.6.1465
日期:2010.6.20
is the chemoselective activation of alkynes (path A) over the activation of ether groups (path B), as shown in Scheme 1. In an effort to extend the scope of this reaction, we envisioned gold(I)-catalyzed cycloisomerization of the corresponding N,S-mixed acetals. Because the thioether groups are known to attack alkynes in the presence of gold catalysts, the main goal of this study was to compare the reactivity
1 10 AgSbF6 (10) rt 20 h 40% 2 10 AgBF4 (10) rt 22 h 40% 3 10 AgOTf (10) rt 4 h 55% 4 10 AgOTf (10) 0 C 10 h 81% 经过两次处理后的分离产率步骤转换。以 15% 的产率分离出 1d。以 7% 的收率分离出 1d。开发合成哌啶的新方法一直吸引着合成化学家的兴趣。最近,我们报道了由高炔丙基胺产生的 N、O 混合缩醛的金 (I) 催化环化异构化,这导致了一种独特的方法来制备高度取代的哌啶-4-酮。该反应的一个关键方面是炔烃的化学选择性活化(路径 A)而不是醚基团的活化(路径 B),如方案 1 所示。为了扩大该反应的范围,我们设想了金(I) - 催化相应的 N,S 混合缩醛的环化异构化。由于已知硫醚基团在金催化剂存在下攻击炔烃,因此本研究的主要目的是比较 N,O-缩醛和 N,S-缩醛在环异