Introducing Trifluoromethoxyarenes as Halide Surrogates in Mechanochemical Realizations of Ni-catalyzed Cross-coupling Reactions

Since the introduction of the TM-catalyzed cross-couplings their scope of starting materials has been growing systematically, allowing for more flexible design of synthetic routes with the coupling as a key step, particularly late-stage modifications. Herein we present the use of trifluoromethoxyarenes as halide surrogates in Ni-catalyzed couplings with arylboronic acids, potassium aryl trifluoroborates and aryl trialkoxysilanes, under mechanochemical conditions. In total, 22 biphenyl structures were obtained in good yields. Successful gram scale experiments confirm the usefulness of our protocol. The developed transformations' mechanism was discussed in relation to the experimental and literature data and DFT calculations. The unusual reactivity of potassium benzoyltrifluoroborates was uncovered. 6 examples of resulting benzophenones were obtained in very good yields and the protocol was extended to gram scale. The described methods present a powerful tool when combined with the recent advances in organofluorine chemistry.