80025-36-1Relevant academic research and scientific papers
Reaction of Aromatic N-Oxides with Dipolarophiles. IX. Formation of 1:2 Cycloadduct of 2-Alkylpyridine N-Oxides and Phenyl Isocyanates and a Frontier Molecular Orbital Study
Matsuoka, Toshikazu,Harano, Kazunobu,Kubo, Hirofumi,Hisano, Takuzo
, p. 572 - 581 (2007/10/02)
A series of 1:2 cycloadducts of a new type was obtained from the reaction of 2-alkylpyridine N-oxides with phenyl isocyanates.The reaction mechanism are discussed in terms of frontier molecular orbital theory based on CNDO/2 and MINDO/2 calculations and kinetic data.The small solvent effect and activation parameters (Ea=14 kcal/mol, ΔS=-46 e.u.) observed for the reaction of 2-alkylpyridine N-oxides with phenyl isocyanates indicate that the cycloaddition proceeds via concerted pathways involving little charge separation in the transition state.Keywords - 1,3-dipolar cycloaddition; 2-alkylpyridine N-oxide; phenyl isocyanate; kinetics; frontier molecular orbital; 1:2 cycloadduct; solvent effect; sigmatropic rearrangement
Reaction of Aromatic N-Oxides with Dipolarophiles. V. 1,3-Cycloaddition of 2-Substituted Pyridine N-Oxides with Phenyl Isocyanates
Hisano, Takuzo,Matsuoka, Toshikazu,Fukunaga, Kazuhiro,Ichikawa, Masataka
, p. 3776 - 3781 (2007/10/02)
The reaction of 2,3-lutidine N-oxide (I) with phenyl isocyanate (IIa) in dimethylformamide at 110 deg C gave a 1:2 adduct (IIIa).Under reflux in ethanolic potassium hydroxide, IIIa readily lost a component of IIa and was converted to 5-methyl-6-N-phenylca
