Lin Chuhao, Jin Yujie, Sun Jizeng, Ye Zehua, Chen Tao, Liu Jiyong, Duttwyler Simon
Department of Chemistry, Zhejiang University, 866 Yuhangtang Road, 310058 Hangzhou, China.
Dalton Trans. 2023 Aug 15;52(32):11042-11046. doi: 10.1039/d3dt02275g.
Penta-iodination of the B2-6 positions of the {CB} monocarborane cluster is reported. Products of the structure [2,3,4,5,6-I-CBH-12-X] (X = H, Me, Et, Ph, Br, I) were obtained and fully characterized. X-ray crystal structures of three new compounds confirm this particular substitution pattern. The synthetic method relies on palladium catalysis/B-H activation, assisted by the C1-COOH directing group. The one-pot procedure enables penta-iodination and subsequent decarboxylation under convenient conditions. The B2-6 regioselectivity is complementary to the commonly observed reactivity of {CB} clusters, which follows the trend B12 > B7-11 > B2-6 for electrophilic substitution. Thus, for the first time upper-belt halogenation is achieved without prior modification of the lower-belt positions.
报道了{CB}单碳硼烷簇合物B2-6位的五碘化反应。得到了结构为[2,3,4,5,6-I-CBH-12-X]（X = H、Me、Et、Ph、Br、I）的产物并进行了全面表征。三种新化合物的X射线晶体结构证实了这种特定的取代模式。合成方法依赖于钯催化/B-H活化，并由C1-COOH导向基团辅助。该一锅法能在便利的条件下实现五碘化及随后的脱羧反应。B2-6区域选择性与{CB}簇合物常见的反应活性互补，亲电取代反应的趋势为B12 > B7-11 > B2-6。因此，首次在未预先修饰下带位置的情况下实现了上带卤化。
