Arsenic Halogenation of 9‑Arsafluorene and Utilization for As–C Bond Formation Reaction

A practical arsenic halogenation
of 9-arsafluorene, which can be safely and easily prepared from a
cyclooligoarsine, was developed by using halogen sources such as iodine
and iodine monochloride. The in situ prepared 9-halogeno-9-arsafluorenes
reacted with various nucleophiles to provide 9-arsafluorene derivatives.
The functional groups affected their emission properties in the solid
state through changes in the packing structure. To estimate the reaction
mechanism of the halogenation, density functional theory calculations
were employed; the molecular behaviors of oxidative addition and reductive
elimination on the arsenic atom were elucidated. Furthermore, the
present reaction was applied to a structure other than 9-arsafluorene
as well.

本研究开发了一种基于9-砷杂芴（9-arsafluorene）的实用卤化方法，该底物可由环低聚胂（cyclooligoarsine）安全便捷地制备，所使用的卤源包括碘（iodine）与一氯化碘（iodine monochloride）。原位制备得到的9-卤代-9-砷杂芴可与多种亲核试剂（nucleophiles）反应，生成一系列9-砷杂芴衍生物。官能团可通过改变固态下的分子堆积结构，对该类衍生物的发光性能产生影响。为阐明该卤化反应的反应机理，本研究采用密度泛函理论（Density Functional Theory, DFT）计算，揭示了砷原子上发生的氧化加成（oxidative addition）与还原消除（reductive elimination）分子过程。此外，本反应体系还被拓展至9-砷杂芴以外的其他底物结构。