通过从 1-bromo-4-取代的立方烷中提取溴原子,产生了一系列 4-取代的立方自由基。EPR 观察表明,cubyl 自由基从三乙基硅烷的乙基中提取二级氢原子,主要通过二级组合反应衰变。在-90 o C 时,叔丁氧基从立方烷中提取氢原子的速度至少比环丙烷快26 倍。立方烷上的吸电子取代基大大降低了这一速度。叔丁氧基自由基选择性地从甲基立方烷中提取笼氢而不是伯甲基氢
Halogenation of Cubane under Phase-Transfer Conditions: Single and Double C−H-Bond Substitution with Conservation of the Cage Structure
作者:Andrey A. Fokin、Oliver Lauenstein、Pavel A. Gunchenko、Peter R. Schreiner
DOI:10.1021/ja0032677
日期:2001.3.1
abstraction is more unfavorable (DeltaG(double dagger)(298) = 4.6 and 12.0 kcal/mol). Our computational results nicely agree with the behavior of 1 under PT halogenation conditions (where Hal(3)C(*) is involved in the activation step) and under free-radical photohalogenation with Hal(2) (Della, E. W., et al. J. Am. Chem. Soc. 1992, 114, 10730). The incorporation of a second halogen atom preferentially in
Homolytic reactions of cubanes. Generation and characterization of cubyl and cubylcarbinyl radicals
作者:Ernest W. Della、Nicholas J. Head、Philip Mallon、John C. Walton
DOI:10.1021/ja00053a008
日期:1992.12
A series of 4-substituted cubyl radicals was generated by bromine atom abstraction from 1-bromo-4-substituted cubanes. EPR observations showed that the cubyl radicals abstracted secondary hydrogen atoms from the ethyl groups of triethylsilane and decayed mainly by second-order combination reactions. tert-Butoxyl radicals abstracted hydrogen atoms from cubane at least 26 times more rapidly than from
通过从 1-bromo-4-取代的立方烷中提取溴原子,产生了一系列 4-取代的立方自由基。EPR 观察表明,cubyl 自由基从三乙基硅烷的乙基中提取二级氢原子,主要通过二级组合反应衰变。在-90 o C 时,叔丁氧基从立方烷中提取氢原子的速度至少比环丙烷快26 倍。立方烷上的吸电子取代基大大降低了这一速度。叔丁氧基自由基选择性地从甲基立方烷中提取笼氢而不是伯甲基氢