The ortho-selective alkylation under Zn/CSA-catalysis conditions was similarly observed between unsubstituted phenol (1n) and 2-adamantanol (2h) where a mixture of alkylated products formed, with o-alkylation occurring as the major product (25%), followed by o-/o-dialkylation (14%), and palkylation (8%) (Scheme 3a). This contrasts from the paraselectivity observed in the analogous Fe/HCl-catalyzed Friedel-Crafts alkylation with tertiary alcohols and HFIPmediated alkylation with tertiary alkyl bromides. We postulate that the zinc catalyst plays a role in templating reactivity and that the phenolic group directs reactivity (through a zinc phenolate species). Upon subjecting anisole (9) to the catalysis conditions, only a small amount of the para-alkylated product (p-10) was observed by NMR analysis (Scheme 3b). This observation emphasizes the importance of the phenolic group in directing both reactivity and selectivity. We found that the catalytic Zn/CSA system favors ortho-selectivity (o-11, >16:1 o/p) even with the more hindered tert-butanol at 80 °C, albeit with lower reactivity compared to the Fe/HCl system (Scheme 3c). At 140 °C, the site-selectivity reverses to favor p-11 (40% We turned to kinetics studies to derive a rate law for this transformation using 3-tert-butylphenol (1a) and 2adamantanol (2h) as the model system (Figure ). Initial rates of the alkylation reaction were measured by varying the concentrations of ZnCl2, CSA, phenolic 1a, alcohol 2h, ZnCl2, and CSA (see SI). These experiments revealed the rate to be largely independent of the concentration of ZnCl2, suggestive of saturation kinetics and sequestration by substrate (Figure ). In the absence of ZnCl2, the initial rate deviates significantly (4.3-fold slower) from the trendline in Figure (See SI, Table ) and is indicative of background reactivity proceeding through a different ZnCl2-free mechanism. The initial rates follow a first-order dependence on the concentration of CSA, half-order dependence on the concentration of phenolic 1a, and first-order dependence on the concentration of 2adamantanol (2h), giving the rate law: rate