Modified aryldifluorophenylsilicates with improved activity and selectivity in nucleophilic fluorination of secondary substrates.

Nucleophilic fluorination of secondary aliphatic substrates, especially of halides, still remains a challenge. Among the available reagents, TBAT belongs to one of the best choices due to its stability, affordable price and low toxicity. With the aim to improve its selectivity, we synthesized three analogues modified in the aryl part of the TBAT reagent with one or two electron donating methoxy groups or with one electron withdrawing trifluoromethyl group.

Chloroimidazolium Deoxyfluorination Reagent with HF Anion as a Sole Fluoride Source.

In the study, we introduce an air-stable NHC-based deoxyfluorination reagent ImCl[HF], offering a promising avenue for deoxyfluorination across various substrates. Reagent efficiently fluorinates benzyl alcohols, carboxylic acids, and P(V) compounds without external fluoride sources. A mechanistic study reveals a two-step process involving benzyl chloride as an intermediate, shedding light on the two-step reaction pathway.

Quaternary ammonium fluorides and difluorosilicates as nucleophilic fluorination reagents.

TBAT (tetrabutylammonium difluorotriphenylsilicate) is an excellent homogeneous nucleophilic fluorination reagent, but a high excess of the reagent was reported to be essential. We hence optimized the reaction conditions and compared its nucleophilic fluorination reactivity with that of other common commercial nucleophilic fluorination reagents, such as anhydrous TBAF and TASF (tris(dimethylamino)sulfonium difluorotrimethylsilicate). As the substrates, we employed a standard set of primary and secondary octyl substrates under identical conditions.

Low-temperature modification of Ba(BF)(HO).

The crystal structure of the low-temperature modification of Ba(BF)(HO), barium bis(tetra-fluorido-borate) trihydrate, was determined at 150 K. In contrast to the room-temperature modification, which crystallizes in the space group 222 [ = 7.1763 (6), = 18.

Fluoride and Aluminium in Tea ( L.)-Tea Quality Indicators and Risk Factors for Consumers.

In recent years, the quality and sourcing of tea have gained importance in Europe, but information remains scarce. The aim of this study was to determine the concentrations of fluoride (F) and total aluminium (Al) species in infusions of commercially available teas in Slovenia, and thus in Europe, and to relate them to tea quality and their impact on consumer safety. F concentrations were determined using a fluoride-ion-selective electrode and Al concentrations using inductively coupled plasma optical emission spectroscopy.