The crystal structure and the phase transitions of pyridinium trifluoromethanesulfonate

TfO–···H–O–H Interaction-Assisted Generation of a Silicon Cation from Allylsilanes: Access to Phenylallyl Ferrier Glycosides from Glycals

“…To understand if other pyridinium triflate salts could catalyze the transformation, the reaction was performed with less-bulky lutidine triflate at 50 °C; however, it did not lead to any conversion even after heating for 24 h, which reiterated the specific reactivity of the triflate associated with the sterically bulky 2,4,6-tri- tert -butylpyridine. Akin to TTBPyHCl, the N–H···OTf – distance is 3.25 Å compared to the N–H···Cl – distance of 3.1 Å in the TTBPyHCl salt, which is unusually longer relative to the simple N–H···OTf – distance in the simple pyridinium triflate salt . In addition, surprisingly, the fluorine of the triflate exhibits H-bonding with C–H atoms of [TTBPyH] + rather than the negatively charged oxygen of the triflate anion, unlike in the simple pyridinium triflate.…”

“…which is unusually longer relative to the simple N−H•••OTf − distance in the simple pyridinium triflate salt. 10 In addition, surprisingly, the fluorine of the triflate exhibits H-bonding with C−H atoms of [TTBPyH] + rather than the negatively charged oxygen of the triflate anion, unlike in the simple pyridinium triflate. The N−H + •••OTf − distance in a simple PyHOTf is 2.19 Å.…”