Practical Synthesis of Unsymmetrical Tetraarylethylenes and Their Application for the Preparation of [Triphenylethylene−Spacer−Triphenylethylene] Triads

We have demonstrated that reactions of diphenylmethyllithium with a variety of substituted benzophenones
produces corresponding tertiary alcohols that are easily dehydrated, without any need for purification, to
produce various unsymmetrical and symmetrical tetraarylethylenes in excellent yields. The simplicity of
the method allows for the preparation of a variety of ethylenic derivatives in multigram (10−50 g) quantities
with great ease. The methodology was successfully employed for the preparation of various triphenylethylene (TPE)-based triads (i.e., TPE−spacer−TPE) containing polyphenylene and fluoranyl-based
spacers. The ready availability of various substituted tetraarylethylenes allowed us to shed light on the
effect of substituents on the oxidation potentials (Eox) of various tetraarylethylenes. Moreover, the electronic
coupling among the triphenylethylene moieties in various TPE−spacer−TPE triads was briefly probed
by electrochemical and optical methods.

本研究证实，二苯甲基锂（diphenylmethyllithium）与多种取代二苯甲酮反应可生成对应叔醇；该叔醇无需纯化即可轻松脱水，以优异收率得到各类不对称与对称的四芳基乙烯（tetraarylethylenes）。该方法操作简便，可轻易制备多克级（10~50 g）的各类乙烯类衍生物。本方法还成功用于制备各类基于三苯乙烯（triphenylethylene, TPE）的三元体（即TPE−间隔基−TPE结构），这类三元体包含聚亚苯基与氟醌（fluoranyl）类间隔基。各类取代四芳基乙烯的便捷获取，使得我们能够阐明取代基对不同四芳基乙烯氧化电位（Eox）的影响规律。此外，本研究还通过电化学与光学方法，对各类TPE−间隔基−TPE三元体中三苯乙烯结构单元间的电子耦合效应进行了初步探究。