Structural and solvent effects on rates of solvolysis of secondary alkyl substrates—an update

Abstract

Rate constants for solvolyses of secondary alkyl tosylates in fluorinated media [including hexafluoropropan-2-ol (HFIP), hexafluoroacetone sesquihydrate, and trichloromethylbis(trifluoromethyl)carbinol] are reported. Rates of solvolysis of 2-adamantyl p-toluenesulfonate in 97% (w/w) HFIP-water at 25 C are neither retarded by the addition of NaOTs nor accelerated greatly by NaClO 4 . The -deuterium kinetic isotope effect for solvolyses of 1-(1-adamantyl)ethyl methanesulfonate in 20% acetone-water at 25 C is 1.14. Mechanistic implications of these results are discussed. RESULTSSalt effects on the solvolysis of 2-AdOTs in aqueous HFIP are given in Table 1. As neither 0.03 M LiClO 4 nor

Unusual Solvent Effect on a SN2 Reaction. A Quantum-Mechanical and Kinetic Study of the Menshutkin Reaction between 2-Amino-1-methylbenzimidazole and Iodomethane in the Gas Phase and in Acetonitrile

“…Bimolecular nucleophilic substitution (S N 2) reactions are of great importance for both chemical and biochemical processes. These reactions are very common and occur in different environments, such as the gas phase, − liquid solution, ,,,,− enzymes, − zeolites, and micelles. , The thermodynamics and kinetics of these reactions have been studied extensively by different experimental techniques, for example, mass spectrometry, ,,,, UV−visible spectrophotometry, ,,,,,, conductivity, ,,,, potentiometry, , and NMR spectroscopy …”

“…Bimolecular nucleophilic substitution (S N 2) reactions are of great importance for both chemical and biochemical processes. These reactions are very common and occur in different environments, such as the gas phase, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] liquid solution, 1,3,13,14,[16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] enzymes, [33][34][35][36] zeolites, 37 and micelles. 38,39 The thermodynamics and kinetics of these reactions have been studied extensively by different experimental techniques, for example, mass spectrometry, 6,7,15,20,40 UV-visible spectrophotometry, 16,17,...…”

Extent of Nucleophilic Participation in the Solvolyses of an Aryl Chloromethyl Ether, α,p-Dichloroanisole

“…Indeed the l/m ratios, a measure of the balance between the two effects, were identical at 1.15 and the l/m ratio remains at this value when all 28 solvents are considered for the solvolysis of 1 ( Table 3). The observation that the data points for solvolyses in HFIP-water mixtures lie nicely on the plot suggests that, as previously proposed for solvolyses of isopropyl bromide, 28 there is still appreciable nucleophilic participation, even in the very low nucleophilicity 97% HFIP as solvent.…”

Fluorinated alcohols: powerful promoters for ring-opening reactions of epoxides with carbon nucleophiles

“…(3) strong hydrogen bond donating abilities; and (4) markedly low solvent nucleophilicities (Table 1). 11,[16][17][18][19][20][21] a For 97% (w/w) HFIP-H2O. b For 97% (w/w) TFE-H2O.…”