<sup>13</sup>C and<sup>1</sup>H NMR of Arylnitrones. Substituent Effects of α-Phenyl-<i>N</i>-(<i>p</i>-substituted phenyl)nitrones
作者:Kohji Suda、Toshio Tsujimoto、Masashige Yamauchi
DOI:10.1246/bcsj.60.3607
日期:1987.10
Substituent effects on the chemical shifts of the conjugation sites in α-phenyl-N-arylnitrones (2) have been investigated. Resonance effects predominate at these positions. The electronic effects of the substituents should be treated separately between electron-donating groups and electron-withdrawing ones. A plausible mechanism for the transmission of the substituent effects in 2 has been proposed.
A novel general method for the synthesis of nitrones by reaction of nitroso compounds with anions of aliphatic nitro compounds
作者:I. M. Lyapkalo、S. L. Ioffe、Yu. A. Strelenko、V. A. Tartakovsky
DOI:10.1007/bf01431312
日期:1996.4
Anions of aliphaticnitrocompounds R1R2C=NO2− react with nitroso compounds RNO to give nitrones R1R2C=N(O)R. Salts of nitrocompounds with metals and Et3N, as well as trimethylsilyl nitronates in the presence of F−, can serve as the sources of the anions. The structure of the nitrones was established by NMR spectroscopy. 1,3-Dipolar cycloaddition of a series of the nitrones obtained to olefins was
Activation and Reaction Volumes for [4+2] and [3+2] Additions Involving Maleic Anhydride
作者:V. D. Kiselev、G. G. Iskhakova、E. A. Kashaeva、M. S. Shikhab、M. D. Medvedeva、A. I. Konovalov
DOI:10.1023/b:rugc.0000025148.16991.3a
日期:2003.12
The partial molar volumes of reactants and products of the [3+2] addition of C-(p-nitrophenyl)-N-phenylnitrone to maleic anhydride and of the [4+2] addition of 9,10-dimethylanthracene to the same dienophile were determined, and the reaction volumes were calculated. A new method was suggested for determining the reaction volume. The activation volumes of both reactions were calculated from the dependences of the reaction rates on the external pressure. The volume parameters of the reactions involving the reagents of close size are close. The ratios of the activation volumes to the reaction volumes are unity, which suggests a common concerted mechanism of the reactions. Factors that could be responsible for significant changes in the absolute values of the reaction volume parameters are discussed.
Andreev, S. A.; Sokolova, O. S.; Kogan, L. M., Journal of applied chemistry of the USSR, 1990, vol. 63, # 2.2, p. 376 - 380
作者:Andreev, S. A.、Sokolova, O. S.、Kogan, L. M.、Krol', V. A.
DOI:——
日期:——
An Unprecedented Formal [5 + 2] Cycloaddition of Nitrones with <i>o</i>-Carboryne via Tandem [3 + 2] Cycloaddition/Oxygen Migration/Aromatization Sequence
作者:Da Zhao、Jiji Zhang、Zuowei Xie
DOI:10.1021/jacs.5b09074
日期:2015.11.4
molecules. Cycloaddition reaction has created new opportunities to access heterocycles of great complexity due to its advantage of multiple bond formation in a single step. Here, we describe an unprecedented formal [5 + 2] cycloaddition of nitrone with o-carboryne to afford carborane-fused seven-membered heterocycles. Experimental and theoretical data suggest that a sequence of [3 + 2] cycloaddition, N-O