described by the linear free energy relationship log k2 (20 °C) = sN(N + E), where N and sN are solvent-dependent nucleophile-specific parameters, and E is an electrophile-specific parameter. The electrophilicity parameters E of the investigated acceptor-substituted alkenes were derived from the linear correlations of (log k2)/sN vs. N, and range from –19.8 to –11.1.
在 DMSO 中,在 20 °C 下研究了马来酸酐、N-甲基马来酰亚胺、富马腈、富马酸二乙酯和马来酸二乙酯与吡啶鎓和锍叶立德的反应动力学。发现所有反应都遵循二阶速率定律,可以通过线性自由能关系 log k2 (20 °C) = sN(N + E) 来描述,其中 N 和 sN 是溶剂依赖性亲核试剂 -特定参数,E 是亲电试剂特定参数。所研究的受体取代烯烃的亲电性参数 E 源自 (log k2)/sN 与 N 的线性相关性,范围从 –19.8 到 –11.1。
STEREOCHEMICAL FEATURES OF CYCLOADDITION OF HETEROAROMATIC<i>N</i>-YLIDES. SELECTIVE PARTICIPATION OF THE ANTI AND SYN YLIDES
作者:Otohiko Tsuge、Shuji Kanemasa、Shigeori Takenaka
DOI:10.1246/cl.1985.355
日期:1985.3.5
In the cycloaddition of heteroaromatic N-ylides to symmetrically substituted trans olefins, the anti ylide exclusively participates if the ylide is carbonyl-stabilized, while the syn ylide does if it has a substituent of non-carbonyl type. The cycloadducts isomerize into thermodynamically more stable isomers through a retro reaction.
Stereochemical Study on 1,3-Dipolar Cycloaddition Reactions of Heteroaromatic<i>N</i>-Ylides with Unsymmetrically Substituted Olefinic Dipolarophiles
作者:Otohiko Tsuge、Shuji Kanemasa、Shigeori Takenaka
DOI:10.1246/bcsj.58.3320
日期:1985.11
Regioselectivity and stereoselectivity of the cycloadditions of heteroaromatic N-ylides with unsymmetrically-substituted olefins such as methyl-substituted cis olefins, an acrylate, the related olefins, trans nitro olefins, and other trans olefins have been investigated. These cycloadditions are highly regioselective, while the stereoselectivity depends upon both the electronic and steric nature of