Palladium(II)-Catalyzed Asymmetric Synthesis of (<i>Z</i>)-α-Alkylidene-γ-butyrolactams from (<i>Z</i>)-<i>N</i>-Allylic 2-Alkynamides. Total Synthesis of (−)-Isocynometrine
作者:Wei Xu、Aidi Kong、Xiyan Lu
DOI:10.1021/jo060288w
日期:2006.5.1
Pd(OAc)2 combined with nitrogen-containing ligands catalyzed the cyclization of (Z)-N-allylic 2-alkynamides in acetic acid to afford the α-(Z)-acetoxyalkylidene-γ-butyrolactams in high yield and high stereoselectivity. When chiral nitrogen-containing ligands were used, the catalytic asymmetric protocol was achieved with moderate enantioselectivity (up to 80 °C). The utility of this new methodology
Pd(OAc)2与含氮配体结合在乙酸中催化(Z)-N-烯丙基2-炔基酰胺的环化反应,从而以高收率和高立体选择性提供α-(Z)-乙酰氧基亚烷基-γ-丁内酰胺。当使用手性含氮配体时,以中等对映选择性(最高80°C)实现了催化不对称方案。这种新方法的效用以(-)-异氰基异戊二烯的全合成为例。