Interaction of acetonitrile with trifluoromethanesulfonic acid: unexpected formation of a wide variety of structures

Abstract

Interaction of acetonitrile with trifluoromethanesulfonic acid has been studied by multinuclear NMR and ESI-MS. It has been found that the interaction results in formation of a great variety of different cations and neutral compounds which is controlled by the ratio of CH(3)CN to TfOH. In the presence of an excess of the acid (molar ratio 1 : 8-14) diprotonated N-acetylacetamidine 1 is formed as the major product, which eventually transforms into protonated acetamidine 3 and acetic acid 4. At molar ratio of (1 : 1-2) diprotonated 2,4-dimethyl-6-methylidene-3H-1,3,5-triazine 12, tautomer of the diprotonated trimethyl-s-triazine 11, becomes the main product at an early stage of the reaction and diprotonated 1-(dimethyl-1,3,5-triazin-2-yl)prop-1-en-2-ol 15 at a later stage. In the case of a large excess of acetonitrile (4-20 : 1) trication 17 is formed as a result of the interaction between 11 and 12 along with some oligomers [(CH(3)CN)(3)](n) (n = 4-12).

Myths about the Proton. The Nature of H+ in Condensed Media

“…44 Acetonitrile is a more complicated solvent giving rise to many byproducts from protonation. 45 More coordinating anions such as Cl − can of course replace a solvent molecule but two -coordinated H + is usually .…”

Selective oxidation of glycerol to dihidroxyacetone (DHA): a comparison between neocuproine-Pd(OAc)2 based catalyst and an its dimeric form

“…The monomeric complex (PdNc-C) was synthesized from the reaction between Pd(OAc)2 and Neocuproine [12] . The activation of CH3CN was done using trifluoromethanesulfonic acid (triflic acid) [14][15] . Anhydrous CH3CN and anhydrous reaction condition were necessary to reach the activation ( figure 2).…”

“…In accord with Sheldon and co-workers [14,19] 5.28g (23.52 mmol) of Pd(OAc)2 (reagent grade 98%, by Sigma Aldrich) were dissolved in 250 ml of anhydrous toluene (purity grade 99.8%, by Sigma Aldrich). 5.00 g (24.00 mmol) of neocuproine were dissolved in 50 ml of CH2Cl2 (purity grade ≥99.5%, by Sigma Aldrich).…”

Addition of a Cyclophosphine to Nitriles: An Inorganic Click Reaction Featuring Protio, Organo, and Main‐Group Catalysis

“…To clarify the role of the electrophile in the above reactions, we prepared isolable triflate salts of [( t BuP) 2 P( t Bu)Me] + and [MeCNMe] + as models for the unstable protonated ions [( t BuP) 2 P( t Bu)H] + and [MeCNH] + , respectively. The molecular structure of [MeCNMe][OTf] was determined (see Figure S11), as symmetric alkylnitrilium cations have not previously been structurally characterized…”