通过使用集成的流动微反应器系统,已经开发出一种有效的方法,该方法可通过杂芳基锂的生成以及随后与八氟环戊烯的反应来合成光致变色二硫杂环丁烷。通过有效的温度和停留时间控制,可以在不使用低温条件的情况下进行反应,尽管批量宏观反应需要低得多的温度(<-78°C)。此外,基于选择性引入一个芳基以产生芳基七氟环戊烯,然后引入另一个芳基,已经完成了使用常规间歇式大分子系统时难以实现的不对称二芳烃的合成。实验室规模的系统的生产率约为0.5 mmol min -1。因此,本集成流式微反应器方法是合成各种光致变色二芳基乙烯衍生物的实用方法。
Practical iron-catalyzed dehalogenation of aryl halides
作者:Waldemar Maximilian Czaplik、Sabine Grupe、Matthias Mayer、Axel Jacobi von Wangelin
DOI:10.1039/c0cc01980a
日期:——
An operationally simple iron-catalyzed hydrodehalogenation of aryl halides has been developed with 1 mol% Fe(acac)3 and commercial t-BuMgCl as reductant. The mild reaction conditions (THF, 0 °C, 1.5 h) effect rapid chemoselective dehalogenation of (hetero)aryl halides (I, Br, Cl) and tolerate F, Cl, OR, SR, CN, CO2R, and vinyl groups.
Bis(2,4-dimethyl-5-phenylthiophene-3-yl) having hydrogen, methoxy, diethylamino, or cyano substituents at para-positions of the phenyl groups were synthesized to reveal the effect of the substitution on the absorption coefficient epsilon of the closed-ring forms and the photochemical reactivity. Electron-donating substituents, such as methoxy or diethylamino groups, were found to be effective to increase the absorption coefficient and to decrease the ring-opening quantum yield. The cyclization quantum yield was scarcely affected by the substitution. The conversion from the open- to the closed-ring forms of the diethylamino-substituted compound in the photostationary state under irradiation with 313 nm light was close to 100%.
GRONOWITZ, SALO;NIKITIDIS, GRIGORIOS;HALLBERG, ANDERS, ACTA CHEM. SCAND., 45,(1991) N, C. 632-635
作者:GRONOWITZ, SALO、NIKITIDIS, GRIGORIOS、HALLBERG, ANDERS
DOI:——
日期:——
SHIRIDHAR, D. R.;JOGIBHUKTA, M.;RAO, P. SHANTHAN;HANDA, VIJAY, K., INDIAN J. CHEM., 1983, 22, N 12, 1187-1190
作者:SHIRIDHAR, D. R.、JOGIBHUKTA, M.、RAO, P. SHANTHAN、HANDA, VIJAY, K.
DOI:——
日期:——
CAGNIANT P.; KIRSCH G., C. R. ACAD. SCI. <CHDC-AQ>, 1975, C 281, NO 1, 35-38