The nickel-catalyzed borylation of aryl iodides and bromides with 4,4,6-trimethyl-1,3,2-dioxaborinane was achieved. The mild reaction conditions employed allowed for the inclusion of common functional groups in aryl halides to be tolerated. A DFT study on the catalytic cycle shows that C-B bond formation occurs through sigma-bond metathesis between dialkoxyborane and arylnickel(II) halide intermediates.
Palladium- or Nickel-Catalyzed Coupling Reaction of Dialkoxyboranes with Chloroarenes: Arylation of 1,3,2-Dioxaborolanes or 1,3,2-Dioxaborinanes
The borylation of electron-deficient aryl chlorides with pinacolborane proceeded in the presence of Bu4NI and a catalytic amount of Pd(dba)(2) / bis(2-di-tert-butylphosphinophenyl) ether. The combination of NiCl2(dppp) catalyst and Bu4NBr was also efficient for the borylation of aryl chlorides.