First examples of transition-metal free Sonogashira-type couplings

[GRAPHICS] We report here our observation that, using appropriate reaction conditions, the Sonogashira reaction can be performed without the need for transition-metal catalysts. Our approach involves the use of water as a solvent, poly(ethylene glycol) as a phase-transfer agent, and sodium hydroxide as a base. The methodology works, to differing extents, for aryl iodides and bromides.