Cycloaddition Reactions of CpCo‐Stabilized Cyclobutadiene Derivatives

Abstract

The pyridine derivative 3 is unexpectedly formed upon reaction of the cyclodecadiyne 1 and glutaronitrile 2 in the presence of CpCo(CO)2 as catalyst. Formally this must involve opening of a CC bond of 1. The formation of 3 can be explained in terms of an equilibrium, in which, inter alia, cobaltacyclopentadiene and surprisingly the title compounds participate.