研究室工作进展 Jul 20th, 2010
Research News July 20, 2010
Efficient One-Pot Synthesis of N-Containing Heterocycles by Multicomponent Coupling of Silicon-Tethered Diynes, Nitriles, and Isocyanides through Intramolecular Cyclization of Iminoacyl-Zr Intermediates
Shaoguang Zhang, Wen-Xiong Zhang, and Zhenfeng Xi*
Chem. Eur. J. 2010, 16, 8419-8426.(VIP)
Dedicated to Professor Uwe Rosenthal on the occasion of his 60th birthday
An efficient multi-component synthesis of 5-azaindoles and dihydropyrrolo[3,2-c]azepines was achieved by zirconocene-mediated coupling of silicon-tethered diynes, nitriles and isocyanides. Synthesis, structures and intramolecular cyclization of mono- and bis(iminoacyl)-Zr intermediates were investigated to elucidate the reaction process. Upon hydrolysis, the isolated mono(iminoacyl)-Zr intermediates underwent intramolecular cyclization to afford tetra-substituted 5-azaindoles, while intramolecular cyclization of bis(iminoacyl)-Zr intermediates led to the formation of dihydropyrrolo[3,2-c]azepines. The structure of a bis(iminoacyl)-Zr intermediate, formed via insertion of two molecules of CyNC into the Zr-C bond, and structures of two dihydropyrrolo[3,2-c]azepines were characterized by single-crystal X-ray structural analysis.