The Ullmann reaction is being widely adopted as a strategy for on-surface organic synthesis. Herein, we investigated the Ullmann reaction on a hexagonal boron nitride (h-BN) layer grown on an Ni(111) substrate using scanning tunneling microscopy (STM). We explored the catalytic activity of Cu and Pd atoms dosed with the molecular precursors. We found that the dispersed atoms of both metals effi...

Carbon-nitrogen (C-N) bond-forming reactions of amines with aryl halides to generate arylamines (anilines), mediated by a stoichiometric copper reagent at elevated temperature (>180°C), were first described by Ullmann in 1903. In the intervening century, this and related C-N bond-forming processes have emerged as powerful tools for organic synthesis. Here, we report that Ullmann C-N coupling ca...

We demonstrated an unprecedented example of Ullmann homocoupling reaction of aryl iodides over a novel recyclable gold catalyst comprising Au nanoparticles supported on a bifunctional periodic mesoporous organosilica (Au@PMO).

The copper-mediated aromatic nucleophilic substitution reactions developed by Fritz Ullmann and Irma Goldberg required stoichiometric amounts of copper and very high reaction temperatures. Recently, it was found that addition of relatively cheap ligands (diamines, aminoalcohols, diketones, diols) made these reactions truly catalytic, with catalyst amounts as low as 1 mol% or even lower. Since t...

The Ullmann-type coupling reaction of vinyl bromides and imidazoles in ILs at 90-110 degrees C gave the corresponding N-vinylimidazoles in good to excellent yields by using L-proline as the ligand; the double bond geometry of the vinyl bromides was retained under the reaction conditions.

A convenient and environmentally friendly protocol for the preparation of biaryls at room temperature under continuous flow conditions is reported. A simple reductive homo-coupling Ullmann-type reaction was performed in an H-Cube mini using commercially available supported Pd catalysts under mild reaction conditions, with quantitative conversion to target products. Commercial Pd catalysts were ...