Organic letters

Cobalt-Catalyzed Intramolecular [2+ 2+ 2] Cocyclotrimerization of Nitrilediynes: An Efficient Route to Tetra-and Pentacyclic Pyridine Derivatives

HT Chang, M Jeganmohan, CH Cheng

Index: Chang, Hong-Tai; Jeganmohan, Masilamani; Cheng, Chien-Hong Organic Letters, 2007 , vol. 9, # 3 p. 505 - 508

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Citation Number: 61

Abstract

In this paper, we wish to report the intramolecular [2+ 2+ 2] cocyclotrimerization of nitrilediynes catalyzed by the CoI2 (dppe)/Zn system at 80° C in CH3CN. Under these reaction conditions, various highly substituted nitrilediynes having steric conjunction at the α and β positions to a nitrile group and a bulkier substitution at the terminal carbon of alkyne undergo [2+ 2+ 2] cocylotrimerization to afford tetra-and pentacyclic pyridine derivatives in ...