Boryl sulfonates, borylation with

Solovyev et al. [60] have shown that the IPr-borane complex can be substituted in a number of different feshions. For instance, reduction of alkyl halides or alkyl sulfonates yields the corresponding NHC-stabilized boryl-halide or sulfonate. Reaction with halogen-based electrophiles also yields boryl-halides. Reactions with Lewis or Bronsted acids (e.g., triflic acid) have also proven successful. These various reactions are especially useful since they result in the addition of a good leaving group, which paves the way for subsequent nucleophilic... 

Thus the catalyzed borylation of aryl iodides, bromides, chlorides or sulfonates with HBhg proceeds readily, in excellent yields and chemoselectivi-ties. The products are perfectly stable to air, water and chromatography. It can thus be considered as a good, inexpensive alternative to the analogous Pd-catalyzed borylation with HBpin, particularly when the substrates are sulfonates or electron-rich halides. 

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