Nickel-Catalyzed Ring-Opening of Benzofurans for the Divergent Synthesis of <i>ortho</i>-Functionalized Phenol Derivatives
Changhui Lu, Yueping Lin, Minyan Wang, Jiaming Zhou, Shuo Wang, Huanfeng Jiang, Kai Kang, Liangbin Huang
Abstract
The ring-opening reaction of benzofuran is a highly desirable, yet underdeveloped transformation for the construction of valuable phenol derivatives. Herein, we report a nickel-catalyzed ring-opening transformation of benzofuran with silanes, giving ortho -alkene-, branched/linear alkyl silane-, and alkenyl silane-substituted phenol derivatives selectively. Control experiments and DFT calculations supported Ni–H insertion and β–O elimination to achieve the formal C–O bond activation of benzofuran but not through the direct oxidative addition of nickel (0) into the C–O bond of benzofurans. Further regioselective hydrosilylation or dehydrogenative silylation occurs via Ni(I)–H or Ni(I)–[Si] intermediates to form ortho -branched/linear alkyl silane- or alkenyl silane-substituted phenol derivatives.