Synthesis of Thioalkynes by Desilylative Sonogashira Cross‐Coupling of Aryl Iodides and 1‐Methylthio‐2‐(trimethylsilyl)ethyne

Abstract 1‐Methylthio‐2‐arylethynes were prepared in typically good to excellent yields from aryl iodides and 1‐methylthio‐2‐(trimethylsilyl)ethyne by a desilylative Sonogashira process employing Pd(PPh 3 ) 2 Cl 2 (1 mol %), CuI (10 mol %), and K 2 CO 3 (6 eq) in MeOH‐Et 3 N‐THF (1 : 2 : 2) at rt for 16 h (16 examples, 31–96 % yield). Thienyl and pyridyl iodides (all regioisomers) were similarly converted to 1‐methylthio‐2‐heteroarylethynes (5 examples, 54–82 % yield). The process was extended with similar results to comparable thioalkynes substituted on sulfur by n ‐alkyl, s ‐alkyl, and aryl groups.