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Molecular oxygen is without doubt the greenest oxidant for redox reactions, yet aerobic oxidation is one of the most challenging to perform with good chemoselectivity, particularly on an industrial scale. This collaborative review (between teams of chemists and chemical engineers) describes the current scientific and operational hurdles that prevent the utilisation of these reactions for the production of speciality chemicals and active pharmaceutical ingredients (APIs). The safety aspects of these reactions are discussed, followed by an overview of (continuous flow) reactors suitable for aerobic oxidation reactions that can be applied on scale. Some examples of how these reactions are currently performed in the industrial laboratory (in batch and in flow) are presented, with particular focus on the scale-up strategy. Last but not least, further challenges and future perspectives are presented in the concluding remarks

The steric bulk of the phosphane ligand determines the mechanism of the ArX addition to zero‐valent [PdL2] complexes. This effect has been studied by variation of ligands (catalyst: [Pd(PCxntBu3−n)2]; n=0–3, Cx=cyclohexyl) in Pd couplings of unsaturated electrophiles, and different reaction pathways (A=associative, B=dissociative) identified, depending on the size of the ligand.

A series of novel, well-defined, unsymmetrical poly(ethylene glycol) chains of the type X(OCH(2)CH(2))(n)()Y (where X = protecting group; Y = nucleofuge or a different protecting group; n = 3, 6, 9, 12, 15, 18, and 24) were prepared in high yields by applying orthogonal protecting groups. The purity of the compounds was fully verified by elemental and high-resolution mass spectrometry analyses.

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The title complex 3 has been synthesized and characterized by X-ray crystallography. It undergoes oxidative addition with aryl triflates and iodides by a nondissociative mechanism in THF. The Heck addition product methyl cinnamate was detected at traces from the reaction with phenyl triflate, and from iodobenzene the direct oxidative addition product was characterized. The addition of halides or acetate salts to the system led to modest effects on the rate of oxidative addition of aryl triflates, but resulted in neutral arylpalladium(II) complexes. Addition of lithium or europium salts enhanced the reaction rate, the effect being most pronounced with Eu(OTf) 3 , possibly through promotion of a competing dissociative pathway.

Generation of catalytically active Pd(0) species from Pd(OAc) 2 has been examined, in the context of Suzuki-Miyaura reactions involving substitution of aryl bromides under aerobic and ambient conditions. Using a combination of spectroscopic, microscopic and kinetic measurements, the role of each reaction component is delineated in the speciation of the palladium species. Among the key findings are the effects of O 2 , H 2 O and inorganic base, and implications for catalytic activity.

[reaction: see text] Regioselective additions of arylsulfonamides to vinylarenes, norbornene, and cyclohexadiene were achieved using a copper-diphosphine catayst under mild reaction conditions. These processes appear to be ligand-accelerated.