The Regio- and Stereoselective Synthesis of 1,4-Diarylbut-1-en-3-ynes Having Aryl Groups at the Mutual Syn Positions

(E)-1-aryl-2,4-bis(trimethylsilyl)but-1-en-3-ynes readily undergo protodesilylation and subsequent aerobic, copper-free Sonogashira cross-coupling with aryl halides to form (E)-1,4-diaryl-2-(trimethylsilyl)but-1-en-3-ynes. The proposed one-pot, two-step approach allows access the isomers containing substituents in mutual syn positions. resulting 2-silyl enynes can be further converted by proto- or halodesilylation.