- Diiodomethane-mediated generation of n-aryliminium ions and subsequent [4 + 2] cycloadditions with olefins
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Herein, we report a method for in situ generation of N-aryliminium ions via reactions of N,N-dimethylanilines with diiodomethane. We used the method to prepare tetrahydroquinolines via one-pot three-component reactions between N,N-dimethylanilines, diiodomethane, and olefins. This transformation involves initial reaction of the aniline with diiodomethane to form an iodomethylammonium salt, which undergoes fragmentation accompanied by elimination of methyl iodide to give an N-aryliminium ion, which is trapped by the olefin via [4 + 2] cycloaddition to give the final product. This method for generating N-aryliminium ions requires neither a catalyst nor a strong oxidant, suggesting that it can be expected to find broad utility, especially for substrates that are sensitive to Lewis acids, transition metals, or strong oxidants.
- Zhao, Yu-Quan,Tian, Jun-Jie,Ai, Chong-Ren,Wang, Xiao-Chen
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- Nitrogen and deuterium isotope effects on quaternization of N,N-dimethyl-p-toluidine
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A nitrogen kinetic isotope effect k14/k15 = 1.0019 ± 0.0001, a deuterium kinetic isotope effect kH3/kD3 = 0.83 ± 0.04, and a solvent deuterium isotope effect kH/kD = 1.00 ± 0.05 were measur
- Paneth, Piotr,O'Leary, Marion H.
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- Selective Hofmann alkylation of aromatic-aliphatic diamines in the presence of carbon dioxide
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Selective Hofmann alkylation at arylamino group in carbon dioxide medium was demonstrated on model diamines containing aliphatic and aromatic primary amino groups, namely, 2-H2NC6H4CH2NH2, 3-H2/
- Balybin, Alexei G.,Panov, Yuri M.,Erkhova, Ludmila V.,Lemenovskii, Dmitry A.,Krut'ko, Dmitry P.
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p. 438 - 440
(2019/08/20)
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- PH Influenced molecular switching with micelle bound cavitands
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A series of resorcinarene host-amphiphilic guest complexes have been developed where guest orientation in the host is drastically influenced by pH. Guests appended with a trimethylammonium and a tert-butyl group switch orientation by 180° in response to a
- Kim, Yeon Joo,Lek, Mark T.,Schramm, Michael P.
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supporting information; experimental part
p. 9636 - 9638
(2011/10/05)
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- Influence of positively-charged guests on the superoxide dismutase mimetic activity of copper(II) β-cyclodextrin dithiocarbamates
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The superoxide dismutase (SOD) activity of the Cu(II) complexes of two dithiocarbamate derivatives of cyclodextrin (Cu-C6DTC, Cu-C2DTC), one on the primary (C6DTC) and the other on the secondary (C2DTC) side, was determined in the presence of positively-c
- Fragoso, Alex,Cao, Roberta,D'Souza, Valerian T.
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p. 171 - 180
(2007/10/03)
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- Nitrogen and deuterium kinetic isotope effects on the menshutkin reaction
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Nitrogen and deuterium kinetic isotope effects were measured in the Menshutkin reaction between methyl iodide and a series of para-substituted N,N-dimethylanilines in ethanol. The nitrogen kinetic isotope effect increases for the more electron-donating substituents [0·9989, 1·0032, and 1·0036 for 4-C(O)Me, II and 4-Me, respectively], in agreement with the Hammond postulate. The secondary deuterium isotope effect, however, exhibits the reverse trend (1·045, 0·989, 0·975 per deuterium, for the respective substituents). This discrepancy is rationalized in terms of solvent molecule participation in the transition state.
- Szylhabel-Godala,Madhavan,Rudzinski,O'Leary,Paneth
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- Multiple Structure-Reactivity Relationships for a Menschutkin-type SN2 Reaction
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The mechanism of nucleophilic displacement was studied by using three variable systems of ρX, ρY and ρZ obtained from the change of substituents X, Y and Z for the reaction of (Z)-substituted benzyl (X)-benzenesulphonates with (Y)-substituted N,N-dimethylanilines in aceton at 35 deg C.The coefficient of the interaction term, ρXY, has a value of 0.21 which means that bond-making and -breaking are concerted in the SN2 transition state.In the range Z = H to p-NO2, in which the SN2 mechanism is predicted to be dominant, the ρZY value is very large, 0.5, which means that the interaction between Z and Y is very large. ρZX is ca. 0.06 which means that the interaction is small between X and Z.In contrast, in the range Z = H to p-Me, in which the SN1 mechanism is dominant, the ρZY value is nearly zero, indicating no interaction between Z and Y.Changes of substituent effect and interaction terms, ρXY, ρYZ and ρZX are useful tools for distinguishing wrong reaction mechanisms.
- Yoh, Soo-Dong,Tsuno, Yuho,Fujio, Mizue,Sawada, Masami,Yukawa, Yasuhide
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