Synthesis of Isoquinoline Derivatives via Palladium‐Catalyzed C−H/C−N Bond Activation of
<i>N</i>
‐Acyl Hydrazones with
<i>α</i>
‐Substituted Vinyl Azides
A palladium‐catalyzed cyclization of N‐acetyl hydrazones with vinyl azides has been developed. Various substituted isoquinolines, including diverse fused isoquinolines can be prepared via this protocol in moderate to good yields. Mechanistic studies suggest that α‐substituted vinyl azide serves as an internal nitrogen source. Also, C−H bond activation and C−N bond cleavage have been realized using
Traceless heterocycle synthesis based on transition-metal-catalyzed C-H functionalization is synthetically appealing but has been realized only in monodentate directing systems. Bidentate directing systems allow for the achievement of high catalytic reactivity without the need for a high-cost privileged ligand. The first bidentate directing-enabled, traceless heterocycle synthesis is demonstrated in the
Palladium-Catalyzed CH Oxidation of Isoquinoline N-Oxides: Selective Alkylation with Dialkyl Sulfoxides and Halogenation with Dihalo sulfoxides
作者:Bo Yao、Ren-Jie Song、Yan Liu、Ye-Xiang Xie、Jin-Heng Li、Meng-Ke Wang、Ri-Yuan Tang、Xing-Guo Zhang、Chen-Liang Deng
DOI:10.1002/adsc.201101009
日期:2012.7.9
palladium‐catalyzed CHoxidation of isoquinoline N‐oxides has been developed for regioselectively synthesizing substituted isoquinolines. The method represents the first example of using dialkylsulfoxides as the alkyl sources for the construction of 1‐alkylated isoquinolines. Moreover, the regioselective halogenation of isoquinoline N‐oxides is also successful using dihalosulfoxides as the halide sources
Gold-catalyzed synthesis of isoquinolines via intramolecular cyclization of 2-alkynyl benzyl azides
作者:Zhibao Huo、Yoshinori Yamamoto
DOI:10.1016/j.tetlet.2009.03.129
日期:2009.7
Intramolecular cyclization of 2-alkynylbenzylazides in the presence of AuCl3 and AgSbF6 in THF under a pressured vial at 100 °C gives the corresponding isoquinolines in good yields. Similarly, the five-membered analogs afford the corresponding isoquinolines.