20.500.12556/RUL-152365 From cyclic (alkyl)(amino)carbene (CAAC) precursors to fluorinating reagents experimental and theoretical study Addition of anhydrous HF to the hydrochloride [$^{Me}$CAACH][Cl(HCl)$_{0.5}$] resulted in the formation of salts with high HF content. By stepwise removal of HF in vacuo, we selectively prepared [$^{Me}$CAACH][F(HF)$_2$] (3) and [$^{Me}$CAACH][F(HF)$_3$] (4). We also characterised a salt with [F(HF)$_4$]$^−$ anions within the structure of [$^{Me}$CAACH][F(HF)$_{3.5}$] (5). Compounds with a lower content of HF were not accessible under vacuum conditions. $^{Me}$CAAC(H)F (1) was selectively prepared by abstraction of HF from 3 with CsF or KF, while [$^{Me}$CAACH][F(HF)] (2) was prepared by mixing 3 and 1 in a 1 : 1 ratio. Compound 2 proved to be quite unstable as it tends to disproportionate into 1 and 3. This observation triggered our computational study, in which the structural relationships between CAAC-based fluoropyrrolidines and dihydropyrrolium fluorides were investigated using different DFT methods. The study showed that the results were very sensitive to the computational method used. For a correct description, the quality of the triple-ζ basis set was crucial. Surprisingly, the isodesmic reaction of [$^{Me}$CAACH][F] + [$^{Me}$CAACH][F(HF)$_2$] → [$^{Me}$CAACH][F(HF)] + [$^{Me}$CAACH][F(HF)] did not confirm the low thermodynamic stability of 2. Furthermore, the use of 3 as a nucleophilic fluorinating reagent was tested on a range of organic substrates, as it is the most stable compound in this series. It was found to have the potential to fluorinate benzyl bromides, 1- and 2-alkyl bromides, silanes and sulfonyls with good to excellent yields of the target fluorides. CAAC precursor fluorinating reagent polyhydrogen fluorides CAAC prekurzor fluorirni reagent polivodikovi fluoridi true false true Angleški jezik Slovenski jezik Članek v reviji 2023-11-22 14:09:02 2023-11-22 14:09:07 2023-11-23 03:39:05 0000-00-00 00:00:00 2023 0 0 Str. 9562-9572 iss. 28 Vol. 52 Jul. 2023 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 546 1477-9234 10.1039/d3dt01476b 160299011 d3dt01476b.pdf d3dt01476b.pdf 1 4356E3ED88A773BA607CB1A6FD1C6506 4d02ed4d8e0dabd60e68f3d92303e1c4ce0725b67ecf176f84d2849d3b1cc67e f7f5038d-8939-11ee-916c-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=177849 https://pubs.rsc.org/en/content/articlelanding/2023/DT/D3DT01476B 1 524c0d1f-8938-11ee-916c-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=177848 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0