Three‐Component One‐Pot Synthesis of Unsymmetrical Diarylalkynes by Thermocontrolled Sequential Sonogashira Reactions Using Potassium Ethynyltrifluoroborate

Unsymmetrical diarylalkynes were synthesized in moderate to good yields through a three‐component one‐pot procedure involving thermocontrolled sequential Sonogashira reactions with potassium ethynyltrifluoroborate and two different reactive aryl halides. The one‐pot procedure was initiated by the palladium/copper‐catalyzed Sonogashira coupling of potassium ethynyltrifluoroborate to an aryl iodide or electron‐deficient aryl bromide at 40 °C. Following a subsequent deboronative Sonogashira reaction of the in situ generated potassium (arylethynyl)trifluoroborate, a second coupling to a less‐active electron‐rich aryl bromide at 80 °C, without any additional palladium/copper catalyst or base, gave rise to unsymmetrical diarylalkynes. Unsymmetrical diarylalkynes are synthesized in moderate to good yields through a three‐component one‐pot procedure involving thermocontrolled sequential Sonogashira reactions with potassium ethynyltrifluoroborate and two different reactive aryl halides.