Solvent-free ruthenium trichloride-mediated [2 + 2 + 2] cycloaddition of α,ω-diynes and cyanamides: a convenient access to 2-aminopyridines

Abstract

A convenient access to functionalized 2-aminopyridines via a solventless Ru-catalyzed [2 + 2 + 2] cycloaddition reaction of α,ω-diynes and cyanamides is described. This transformation efficiently proceeds in the presence of a stable, easy to handle, and cost-effective RuCl₃·nH₂O complex, leading to various 2-aminopyridines in good to excellent yields according to an eco-friendly, straightforward approach.