A mild and efficient photocatalytic protocol for the alpha-deuteration of aliphatic amines has been developed using thiobenzoic acid as the HAT catalyst without the extra photocatalyst. This new method can be applied to a variety of aliphatic amines, amides, and carbamates with high deuterium incorporations and isolated yields. Alkylated arenes are also amenable to this reaction, as the deuteration occurs regioselectively at the benzylic positions. Deuteration of active pharmaceutical ingredients is also demonstrated. Primary mechanistic studies indicate an hydrogen atom transfer pathway for this hydrogen isotope exchange process.

Rationale Many perfluoroalkyl and polyfluoroalkyl sulfonic/sulfinic acids and their derivatives are classified as perfluoroalkyl and polyfluoroalkyl substances (PFASs). The use of mass spectrometry techniques to analyze these compounds has attracted considerable research attention.Methods In this article, we employed high-resolution electrospray ionization tandem mass spectrometry (HR-ESI-MS/MS) and all-ion fragmentation (AIF) in negative ion mode to investigate gas-phase F-atom migration reactions of various perfluoroalkyl and polyfluoroalkyl sulfonic/sulfinic anions, particularly those yielding FSO3- or FSO2-.Results HR-ESI-MS/MS of CF3SO3- yielded an unexpected product ion FSO3-, representing a distinct pathway of gas-phase F-atom migration from C-atom to S-atom accompanied by the loss of CF2. Similarly, HR-ESI-MS/MS of CF3SO2- produced a dominant product ion FSO2- also via CF2 elimination. Complementary ESI-MS/MS and AIF experiments on these anions confirmed that FSO2- and/or FSO3- are their characteristic fragmentation ions.Conclusion Theoretical calculations of gas-phase reactions CF3SO3- -> FSO3- + CF2 and CF3SO2- -> FSO2- + CF2 were performed to investigate the possible F-atom migration mechanisms. These results show that FSO3- at m/z 99 and/or FSO2- at m/z 83 could serve as diagnostic ions for structural elucidation of perfluoroalkyl and polyfluoroalkyl sulfonic/sulfinic acids and their derivatives in non-target PFASs analyses by using mass spectrometry.

The development of efficient and sustainable catalytic systems based on earth-abundant metals for hydrogen storage and green organic synthesis represents a significant and urgent challenge. While ammonia borane (AB) is a promising hydrogen carrier, its catalytic dehydrogenation and subsequent transfer hydrogenation have predominantly relied on precious-metal catalysts, and existing cobalt-based systems often lack the combination of ultrahigh activity and broad utility. Addressing this gap, this work introduces a well-defined macrocyclic bispyridyldiimine-supported binuclear cobalt complex that serves as a highly efficient catalyst for both AB dehydrogenation, achieving high H-2 release and a wide range of AB-mediated transfer hydrogenation reactions under mild conditions. The system demonstrates exceptional performance by facilitating the reduction of diverse substrates-including alkenes, indoles, nitriles, and carbonyl compounds-in high yields. Its unprecedented activity is highlighted by the transfer hydrogenation of olefins at an ultralow catalyst loading of just 0.01 mol%, and its capability to hydrogenate challenging substrates like indoles at room temperature, overcoming the need for traditional harsh conditions. A key mechanistic insight is the distinct bimetallic advantage: the corresponding mononuclear cobalt complex is catalytically inactive under identical conditions, underscoring that the superior activity arises from the synergistic binuclear structure. These findings establish synergistic binuclear cobalt catalysis as a highly active, and sustainable platform for reductive transformations using AB, fundamentally advancing the field of earth-abundant metal catalysis.