Palladium‐Catalyzed Cross‐Coupling Reactions – Industrial Applications

Light‐ and Manganese‐Initiated Borylation of Aryl Diazonium Salts: Mechanistic Insight on the Ultrafast Time‐Scale Revealed by Time‐Resolved Spectroscopic Analysis

“…Aryl boronates are important building blocks within organic synthesis, withoutq uestion due to the ubiquity of the Suzuki-Miyaura reaction,w hichr anks in the top-five most used reactions in target-orientateds ynthesis, [1] across the pharmaceutical and agrochemical industries. [2,3] The mostc ommon methods for their preparation involve either the stoichiometricm etalation (to organo-lithium or Grignardr eagents) or the Miyaura borylation [4] of aryl halides. The former approach suffers from limited functionalg roup tolerance and the need for anhydrous conditions and controlled reagent addition, whereas the latter requiresP dc atalysis.…”

From imine to amine: an unexpected left turn. Cis-β iron(ii) PNNP′ precatalysts for the asymmetric transfer hydrogenation of acetophenone

“…In greater detail, 1-bromo-2-fluorobenzene was chosen as the coupling reagent to monotosylated-( S , S )-DPEN in order to selectively perform Buchwald–Hartwig amination on the bromo substituent, leaving the fluoro group unaltered for subsequent phosphination. 18 – 21 This reaction was scaled up to produce 3 g of benzoFTsDPEN ( 7 ) at the cost of refluxing in toluene for several days. Nucleophilic aromatic substitution using bulky potassium diphenylphosphide proceeded slowly in refluxing THF due to the kinetic barrier imposed by the sterically-encumbered ortho position.…”

“… 17 The objective of this investigation was to replace the C C bond with an orthophenylene group to prevent reduction and shut down the deactivation pathway and allow the recycling of the catalyst. Recent developments in palladium-catalyzed amination 18 – 21 allowed us to afford the key PNN building blocks needed to prepare the precatalysts 5a–f and 6a–e , shown in Fig. 2 in their major diastereomeric form.…”

Palladium-catalyzed allene synthesis enabled by β-hydrogen elimination from sp2-carbon

“…Palladium catalysis has proved to be a powerful synthetic tool, which is demonstrated by numerous useful transformations and highlighted by the 2010 Nobel Prize in chemistry. [1][2][3] Although the mechanism involved in those reactions have been extensively explored, efforts to acquire a deep understanding of the current mechanistic hypothesis and apply them to design new transformations have never ceased. As a elementary reaction in palladium catalysis, β-hydrogen elimination has been well studied (Fig.…”