Substituted phenols are alkylated exclusively at the lesshindered position(s) ortho to the phenolic group. Both 3-ethyl and 3-tert-butylphenol are converted to tert-butylated 3ea and 3fa in 58% and 92% yields, respectively, the latter of which is confirmed by X-ray crystallography (see SI). The higher isolated yield obtained for 3fa is presumably due to the lack of benzylic hydrogens that can participate in hydrogen atom abstractions. 3-Phenylphenol, which also does not contain benzylic hydrogens, is transformed into the corresponding alkylated product (3ga) in 73% yield. The phenolic derivative bearing a meta-chloro substituent undergoes tert-alkylation to yield phenolic 3ha in a modest 41% yield. Contrary to phenolic substrates 1a-h that are monoalkylated at the less hindered ortho site, 3-methoxy-and 3-fluorophenol are tert-butylated at both the 4-and 6-positions to furnish tetrasubstituted phenols 3iaa and 3jaa, in 90% and 62% yields, respectively, with 1 equivalent of DTBP (2). ortho-Substituted phenolic substrates are considerably less reactive but are selectively tert-butylated para to the hydroxy group to yield 3ba, 3ka and 3la in 22-44% yields when conditions involving higher iron loadings and extended reaction times are used.