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 silanesubstituted 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.

Thioketene, as a highly reactive intermediate, is extremely prone to dimerization, which severely limits its further synthetic application. Herein we developed a Cu-catalyzed thioacylation of amines via C-H activation/coordinated stabilization...

Directed C–H arylations have proven to be some of the most advantageous strategies for the synthesis of biaryls. However, their sensitivity towards steric hindrance is a key limitation. Couplings of 2,6-disubstituted aryl halides with arenes have so far been elusive. This weakness is overcome by a ruthenium 3,4,7,8-tetramethyl-1,10-phenanthroline catalyst. It allows the selective ortho-C–H arylation of widely available (hetero)aromatic acids with bulky aryl halides in up to 95% isolated yield. 46 Examples of tri-substituted (hetero)biaryls, all outside the scope of established catalyst systems, demonstrate the efficiency of the protocol. Computational and experimental studies illustrate how this unique combination of carboxylate directing group and chelating N-ligand facilitate selectivity determining C–H activation step. The preference for oxidative addition of the aryl halide over competing benzoic acid coordination is decisive to suppress unwanted dehydrogenative homo-coupling.

Shown herein is the first time that the dibenzofurans are utilized for SNAr reaction with various nucleophiles, including primary and secondary alcohols, aliphatic amines and phosphines. A series of functional...