C–H Borylation Catalysts that Distinguish Between Similarly Sized Substituents Like Fluorine and Hydrogen

• DOI: 10.1021/acs.orglett.9b02299
• Publication Date: 2019-08-08T12:45:10Z
• Authors: Susanne L. Miller; Ghayoor A. Chotana; Jonathan A. Fritz; Buddhadeb Chattop...; Robert E. Maleczka; Milton R. Smith
• Keywords: Borylation; Fluorine

By modifying ligand steric and electronic profiles it is possible to C-H borylate ortho or meta substituents in aromatic heteroaromatic compounds, where differences between accessible sites are small. Dramatic effects on selectivities reactions using B2pin2 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (HBpin) described for the first time. Judicious borane combinations give highly regioselective borylations substrates typical borylation protocols afford poor selectivities.