Initial experiments were performed with Kobayashi's 2-(trimethylsilyl)phenyltrifluoromethanesulfonate (1) and PPi (18) as a potential arynophile. An overview of the reaction optimization is shown in the SI (supporting table ). In short, MeCN was identified as the optimal solvent, by enabling complete dissolution of the phosphates as tetrabutylammoniumsalts (TBA) while maintaining aryne reactivity. TBAF (1 M in THF) was the ideal fluoride source as inorganic fluoride salts like CsF induced the precipitation of insoluble pyrophosphate metal salts. The rate and order of reagent addition turned out to play a critical role during reaction optimization. The highest yields were achieved, when TBAF was added slowly within 1 h via a syringepump to a solution of phosphate and aryne-precursor in MeCN. Notably, the reaction can be performed under ambient conditions without exclusion of moisture.