Nucleophilic addition to olefins. Part 25. Kinetics of hydrolysis of substituted .beta.-nitrostyrenes. Transition-state imbalances and intrinsic rate constants for three different types of nitronate ion forming processes. Relevance to the nitroalkane anomaly

Abstract

The palladium-catalyzed trimethylenemethane (TMM) cycloaddition of carbonyl compounds has been shown to have a strong dependence upon the presence of cocatalysts such as tri-n-butyltin acetate, di-n-butyltin diacetate, or trimethyltin acetate. High-yielding annulations of aldehydes were accomplished either by using TMM precursors that contain the elements of trialkyltin acetate (which is then generated in situ) or by using silicon-based precursors and an exogenous cocatalyst.

Electrophilicities oftrans-β-Nitrostyrenes

“…Additions of oxindols to nitroalkenes have been performed under conditions of phase-transfer catalysis, 26 and tandem cycloadditions of nitroalkenes 27,28 have been applied to the synthesis of natural products. 29 Kinetics of the reactions of nitroalkenes with benzylamines, 30 sodium alkoxides, 31 and hydroxide anions 32 have been investigated in order to elucidate the mechanism of nucleophilic additions to the electron-deficient double bond of nitroalkenes. 33 In previous work, we have shown that a large variety of reactions of electrophiles with nucleophiles can be described by eq 1, where N and s N (previously called s) are nucleophilespecific parameters, E is an electrophilicity parameter, and k 2 is the second-order rate constant.…”

“…Kinetics of the reactions of nitroalkenes with benzylamines, sodium alkoxides, and hydroxide anions have been investigated in order to elucidate the mechanism of nucleophilic additions to the electron-deficient double bond of nitroalkenes …”

Physical Organic Chemistry of Transition Metal Carbene Complexes. 17.1 Kinetics of the Reactions of (Arylthioalkoxycarbene)pentacarbonyl Complexes of Chromium(0) and Tungsten(0) with Thiolate Ions in Aqueous Acetonitrile: pKa Values of the Metal-Protonated Tetrahedral Adducts Formed between Carbene Complexes and Thiolate Ion

“…Such p K a values of Fischer carbene complex adducts have, thus far, been elusive. A kinetic p K a determination might be possible by reacting, say, 6-M - with acid which leads to regeneration of 5-M, preceded by rapid reversible protonation of 6-M - on the metal, a situation akin to the reaction of nitronate ions where rapid reversible nitronic acid formation precedes slow carbon protonation or leaving-group departure …”

Formation of 2,6-Bis(4-chlorophenyl)-5,6-dihydro-2H- 1,3,4-oxadiazine-4-oxide by an Intramolecular Amino/Nitro Dehydration

“…The resulting organic solution was washed with water, dried over Na 2 SO 4 , and then concentrated. The residue was purified by column chromatography (silica gel/hexane:ethyl acetate = 8:1) to give 2-nitro-1-(4‘-chlorophenyl)ethanol , ( 1 ) as a yellow oil (0.24 g, 6% yield; 1 H NMR (CDCl 3 ) δ 7.37 (4H, AB), 5.43 (1H, dd, J = 9.5 and 3.0 Hz), 4.57 (1H, dd, J = 13.5 and 9.5 Hz), 4.48 (1H, dd, J = 13.5 and 3.0 Hz), 3.18 (1H, br s); 13 C NMR (CDCl 3 ) δ 136.72, 134.90, 129.32, 127.50, 81.11, 70.44), 4-chloro-β-nitrostyrene ( 2 ) as pale yellow needles, mp 111.5−112.5 °C (lit . mp 111−112 °C) (2.39 g, 65% yield; 1 H NMR (CDCl 3 ) δ 7.95 (1H, d, J = 14.0 Hz), 7.56 (1H, d, J = 14.0 Hz), 7.49 (2H, d, J = 8.5 Hz), 7.42 (2H, d, J = 8.5 Hz); 13 C NMR (CDCl 3 ) δ 138.53, 137.88, 137.63, 130.46, 129.97, 128.74), and 3 (0.50 g, 15.5% yield: 1 H NMR (CDCl 3 ) δ 8.32 (1 H, s), 7.71 (2 H, d, J = 8.5 Hz), 7.44 (2 H, d, J = 8.5 Hz), 7.38 (4 H, d, J = 8.5 Hz), 5.12 (1 H, dd, J = 10.0 and 4.0 Hz), 4.89 (1 H, dd, J = 12.5 and 10.0 Hz), 4.69 (1 H, dd, J = 12.5 and 4.0 Hz); 13 C NMR (CDCl 3 ) δ 162.50, 137.40, 136.65, 134.17, 133.65, 129.75, 129.12, 128.82, 128.46, 80.54, 70.64; MS m / z 323 (MH + ) 288, 275, 262, 240, 227, 214, 199, 191, 183, 165, 150, 138, 125, 111, 103, 89, 75; HRMS calcd for C 15 H 13 Cl 2 N 2 O 2 (MH + ) 323.0354, found 323.0329.…”