This two-step formal dehydration of arenes is compatible with a variety of functional groups and arene substitution patterns (Scheme 2). Beyond chlorobenzene 1a, bromo and fluorobenzene, 1b and 1c, respectively, are compatible and the aryne is formed in a remote location relative to the halide (Scheme 2). Arenes with 1,4-substitution patterns are well tolerated (1d-f), as are those with 1,2-substitution patterns (Scheme 2, 1g-i). Additionally, these substrates demonstrate that all halides (F, Cl, Br, I) and nitrile groups are compatible with the reaction conditions (Scheme 2). A variety of 1,2,4-substituted arenes, which are commonly found in commercial building blocks and drugs, are compatible in this transformation. In all cases the aryl halide is left intact and a penta-substituted arene is obtained (Scheme 2, 1j-o). We observed that basic (pyridine), mildly acidic (terminal alkyne), and electrophilic (ketone) functional groups participate in the two-step formal dehydrogenation reaction in moderate to high yield (Scheme 2, 1qs). It is important to point out that several of the substrates presented in Scheme 2 (1a,b,j,o) have been used to access arynes by ejection of the halide leaving group, but we observed that under our conditions aryne formation occurs at a remote position in all of these cases. Moreover, when multiple arenes are present in a substrate (i.e., 1i, 1p, 1q, 1s) the aryne is formed on the more electron-rich arene because this is the site of initial thianthrenation. Finally, using arene 1o we telescoped the two step dehydrogenation in a single pot without removing the thianthrenium intermediate 1o(TT + ) and the aryne adduct 2o was obtained in 85% yield, which is almost identical to the non-telescoped process. 13 Scheme 2. Scope of aryl halides. a a Conditions: Step 1: 1a-t (0.5 mmol, 1 equiv.), TTO (0.5 mmol, 1 equiv.), TfOH (0.75 mmol, 1.5 equiv.), TFAA (1.5 mmol, 3 equiv.) MeCN (2 mL), r.t., 1 hour. Step 2: 1a-t(TT + )TfO -(0.5 mmol, 1 equiv.), furan (2.5 mmol, 5 equiv.), NaO t Bu (1 mmol, 2 equiv.), toluene (2.5 mL), 65 °C, 1 hour; yields refer to step 1, step 2, and overall yield in parentheses. b Reaction conducted in 1,4-dioxane.