Corrigendum: Acyl-directed ortho-borylation of anilines and C7 borylation of indoles using just BBr₃

On repeating pivaloyl directed indole borylation in dichloromethane (DCM) with BBr₃ (1 m in heptanes or hexanes), the formation of small quantity of precipitate was observed in a number of cases at the 5 x-BBr₂/6 x-BBr₂ stage. Previously the authors of this Communication had reported the C2:C7 borylation ratio (at the BBr₂ stage) based on in situ solution ¹H NMR spectroscopy (in DCM/hexanes (or heptanes) mixes), thus they reassessed all of these ratios using a different procedure. Specifically, borylation was performed in DCM using 1 m BBr₃ in DCM using otherwise identical conditions to those we previously reported. This led to homogenous solutions in most cases, and where solid was observed the sample was diluted with DCM until it was homogenous and then analysed. This led in three cases to different ratios to that originally reported (due to the different solubility of 5 x-BBr₂ vs 6 x-BBr₂), thus three ratios in the table on page 31 of the Supporting Information should be corrected to those below. The 5 k-BBr₂/6 k-BBr₂ ratio was checked further by performing the borylation as previously described (in DCM with 1 m BBr₃ in heptanes), reducing the sample to dryness in vacuo and dissolving a portion of the resultant solid in DCM for analysis by NMR spectroscopy. 6-fluoro (starting compound 2 d) + BBr₃ → C7-BBr₂:C2-BBr₂ ratio = 90:10 6-chloro (starting compound 2 k) + BBr₃ → C7-BBr₂:C2-BBr₂ ratio = 91:9 6–bromo (starting compound 2 l) + BBr₃ → C7-BBr₂:C2-BBr₂ ratio = 86:14 Thus the brief discussion on the isomerisation of 5 k-BBr₂/6 k-BBr₂ during pinacol installation is not warranted. The authors apologise for this error. All other statements in the manuscript remain valid.