Effect of physicochemical congestion on the catalytic conversion of arylboronic acids to phenols.

Intense research efforts have been devoted to establishing congestion of molecules as an additional control parameter of chemical conversion. This manuscript describes designing a novel catalytic system where the rate of catalytic conversion is enhanced by nanometric congestion, using catalytic hydroxylation of arylboronic acids as the model system. An aqueous dispersion of catalytic Ni(OH)₂ nanosheets (Ni-NS) can be reversibly assembled and disassembled into lamellar membranes (Ni-NS-M), forming molecularly thin two-dimensional nanofluidic reactors. Remarkably, the hydroxylation rate of several arylboronic acids inside nanofluidic channels was found to be significantly different from the reactions conducted under bulk stirring conditions. The changing vibrational patterns of the reactants and the electrostatic forces of the channel walls within atomically thin channels of Ni-NS are attributed to the increased reaction rate.