Although O2 is an ideal oxidant in the transformation of methane, very limited studies realize this process in homogeneous solvent systems with high efficiency under mild conditions. Herein, we present a NaCl-promoted cobalt-catalyzed O2-mediated methane oxidation with turnovers over 700 at 120 °C with a dramatic salt effect. The unexpected methylene bis(trifluoroacetate) can be produced with a selectivity up to 90%. This product is used in the reaction with TsNH2 and 1,2-diimine to efficiently form triazinane and imidazole salt, respectively. The Co-NaCl catalytic system is also applied in the oxidation of other hydrocarbons such as adamantane, 9,10-dihydrophenanthrene, 9,10-dihydroanthracene, and 9,10-dihydroacridine. Mechanistic studies indicate that NaCl can promote the decomposition of trifluoroacetic anhydride (TFAA) in the presence of Co(II), and a highly reactive fluorine radical might be formed to react with methane, generating a methyl radical, which will further react with O2 and then with trifluoroacetic anhydride to form methylene bis(trifluoroacetate).

Poly(3-hydroxyalkanoates) (PHAs) are an important category of biodegradable plastics with properties similar to those of conventional ones. The development of a simple and efficient catalytic system for PHAs from the most abundant chemicals is economically important. Now we report an in situ generated bifunctional cobalt-catalyzed direct carbonylation-polymerization of epoxides in high efficiency in the presence of a diphosphine oxide ligand WenPhos oxide, which can be easily made from diphenyl sulfone in three steps with regular reagents. In addition, this ligand can promote the disproportionation of Co2(CO)8 to [Co(CO)4]− and Co(II) which is coordinated with phosphine oxide and sulfone oxide. Mechanistic studies indicate that this reaction is not from the ring-opening polymerization of in situ generated β-lactone. Instead, the phosphine oxide coordinated cobalt cation and [Co(CO)4]− anion pair catalyzed direct carbonylation-polymerization of epoxide was proposed based on previous studies, some control experiments, and X-ray structures of the cobalt complexes.

We report a mild and efficient hydrotrifluoromethylation of alkenes with bromotrifluoromethane (CF3Br) mediated by zinc and Brønsted acid. This reaction performs well with good functional group compatibility and broad substrate...

Trifluoromethylphosphines represent a rare kind of phosphine with unique electronic withdrawing properties, which lead to some distinctive reactivities. The reported TFMPhos, products from nucleophilic or electrophilic trifluoromethylation of substrates, requiring one or more steps and prepared from phosphine chlorides, are very limited in structure diversity. Herein, we report a convenient and scalable (up to 100 mmol) recipe to synthesize diverse trifluoromethylphosphines via direct radical trifluoromethylation of phosphine chlorides with CF 3 Br in the presence of zinc powder.