American Chemical Society
jo101596d_si_003.cif (14.7 kB)

Rh-Catalyzed Oxidative Coupling between Primary and Secondary Benzamides and Alkynes: Synthesis of Polycyclic Amides

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posted on 2010-11-05, 00:00 authored by Guoyong Song, Dan Chen, Cheng-Ling Pan, Robert H. Crabtree, Xingwei Li
A methodology for the high yield and facile synthesis of isoquinolones from benzamides and alkynes via the oxidative ortho C−H activation of benzamides has been developed. Ag2CO3 proved to be an optimal oxidant when MeCN was used as a solvent, and [RhCp*Cl2]2 was utilized as an efficient catalyst. Both N-alkyl and N-aryl secondary benzamides can be applied as effective substrates. Furthermore, primary benzamides react with two alkyne units, leading to tricyclic products via double C−H activation and oxidative coupling. The reactivity of the structurally related 1-hydroxyisoquinoline was also demonstrated, where both N- and O-containing rhodacyclic intermediates can be generated, leading to the construction of different O- or N-containing heterocycles.