Two Directing Groups Used for Metal Catalysed -C-H Functionalisation Only Effect Electrophilic C-H Borylation.

Two templates used in -directed C-H functionalisation under metal catalysis do not direct -C-H borylation under electrophilic borylation conditions. Using BCl only Lewis adduct formation with Lewis basic sites in the template is observed. While combining BBr and the template containing an amide linker only led to amide directed C-H borylation, with no pyridyl directed borylation. The amide directed borylation is selective for the borylation of the aniline derived unit in the template, with no borylation of the phenylacetyl ring - which would also form a six membered boracycle - observed. In the absence of other aromatics amide directed borylation on to phenylacetyl rings can be achieved. The absence of -borylation using two templates indicates a higher barrier to pyridyl directed borylation relative to amide directed borylation and suggests that bespoke templates for enabling -directed electrophilic borylation may be required.