Alexander Wagner

Bio: Alexander Wagner is an academic researcher from Ludwig Maximilian University of Munich. The author has contributed to research in topics: Cyanation & Allylic rearrangement. The author has an hindex of 3, co-authored 6 publications receiving 109 citations.

Potassium Thiocyanate as Source of Cyanide for the Oxidative α-Cyanation of Tertiary Amines

Abstract: Oxidation at the sulfur of the safe-to-handle potassium thiocyanate releases cyanide units that are trapped in the presence of co-oxidized tertiary amines to form α-amino nitriles. These cyanations work in aqueous solutions and do not require a catalyst, nor do they form toxic byproducts.

Potassium Thiocyanate as Source of Cyanide for the Oxidative α-Cyanation of Tertiary Amines.

Abstract: KSCN is oxidized at the sulfur to produce a cyanide unit which is trapped by the co-oxidized amines with formation of α-aminonitriles.

Activation and discovery of earth-abundant metal catalysts using sodium tert -butoxide

Abstract: First-row, earth-abundant metals offer an inexpensive and sustainable alternative to precious-metal catalysts. As such, iron and cobalt catalysts have garnered interest as replacements for alkene and alkyne hydrofunctionalization reactions. However, these have required the use of air- and moisture-sensitive catalysts and reagents, limiting both adoption by the non-expert as well as applicability, particularly in industrial settings. Here, we report a simple method for the use of earth-abundant metal catalysts by general activation with sodium tert-butoxide. Using only robust air- and moisture-stable reagents and pre-catalysts, both known and, significantly, novel catalytic activities have been successfully achieved, covering hydrosilylation, hydroboration, hydrovinylation, hydrogenation and [2π+2π] alkene cycloaddition. This activation method allows for the easy use of earth-abundant metals, including iron, cobalt, nickel and manganese, and represents a generic platform for the discovery and application of non-precious metal catalysis.

Room temperature decarboxylative cyanation of carboxylic acids using photoredox catalysis and cyanobenziodoxolones: a divergent mechanism compared to alkynylation.

Abstract: The one-step conversion of aliphatic carboxylic acids to the corresponding nitriles has been accomplished via the merger of visible light mediated photoredox and cyanobenziodoxolones (CBX) reagents. The reaction proceeded in high yields with natural and non-natural α-amino and α-oxy acids, affording a broad scope of nitriles with excellent tolerance of the substituents in the α position. The direct cyanation of dipeptides and drug precursors was also achieved. The mechanism of the decarboxylative cyanation was investigated both computationally and experimentally and compared with the previously developed alkynylation reaction. Alkynylation was found to favor direct radical addition, whereas further oxidation by CBX to a carbocation and cyanide addition appeared more favorable for cyanation. A concerted mechanism is proposed for the reaction of radicals with EBX reagents, in contrast to the usually assumed addition elimination process.

PEGylated magnetic nanoparticles (PEG@Fe3O4) as cost effective alternative for oxidative cyanation of tertiary amines via CH activation

Abstract: An efficient, cost effective and environmental friendly PEGylated magnetic nanoparticle catalyzed oxidative cyanation via C H activation of tertiary amines to corresponding α-aminonitriles using hydrogen peroxide as oxidant and sodium cyanide as cyanide source is described. The synthesized nanocatalyst was easily recovered with the help of external magnet and was successfully reused for several runs without any significant loss in catalytic activity.