Pinacolborane as the Boron Source in Nitrogen-Directed Borylations of Aromatic N,N‑Dimethylhydrazones

A mild procedure for the Ir­(III)-catalyzed nitrogen-directed ortho borylation of aromatic N,N-dialkylhydrazones using pinacolborane as the boron source has been developed. The methodology relies on a modified, hemilabile N,N ligand built on a 4-N,N-dimethylaminopyridine unit that provides high reactivity while maintaining exclusive ortho-selectivity. This procedure can be combined with Suzuki–Miyaura cross-couplings in a ‘one-pot’ fashion to afford functionalized biaryl derivatives that, upon subsequent ‘one-pot’, high yielding transformations, provide a convenient entry for the preparation of advanced benzonitrile intermediates for the synthesis of Sartan-type drugs.