Development of Tunable Single-Electron Transfer Reagents.

设计并澄清了单电子可释放络合物，即三甲基锰酸锂(Me_3Mn(II)Li)、三甲基高铁酸锂(Me_3Fe(II)Li)和三甲基钴酸锂(Me_3Co(II)Li)。用从头计算、原位FTIR光谱和电化学方法讨论了它们的单电子转移(以下简称SET)反应的本质和机理。结果表明，这些配合物是SET反应的高效、选择性的络合剂，并能在一定程度上通过配位环境控制其单电子释放能力。基于所获得的电化学信息，我们还开发了该SET系统的催化版本。该体系对所有类型的N-苯磺酰胺类化合物的脱磺化反应、邻烯丙基/苄基/对甲苯甲基/叔丁基二甲基硅基(TBDMS)的化学选择性脱保护、硝基的还原、二酮的部分羰基还原、二苯基碘盐的还原配体偶联以及二卤代化合物通过阴离子自由基类的二芳基还原偶联反应都是有效的，在温和的条件下产率很高。由于以下几个原因，该系统是一种非常有吸引力的方法(简单、有效、低成本和易于操作)，并且特别适用于大规模反应。

The single-electron releasable ate complexes (hereafter denoted as "SER-ate complex"), i.e., lithium trimethylmanganate (Me_3Mn(II)Li), lithium trimethylferrate (Me_3Fe(II)Li), and lithium trimethylcobaltate (Me_3Co(II)Li) have been designed and clarified. We also discussed the essence and mechanism of their single-electron transfer (hereafter called SET) reaction using ab initio theoretical calculations, in situ (ATR)FTIR spectroscopy, and electrochemical methods. The results clearly reveal that these complexes are powerful and selective complex reagents for the SET reaction and can control their single-electron releasing ability to some extent by the ligation environment. Based on the obtained electrochemical information, we also developed the catalytic version of this SET system. This system turned out to be effective for the desulfonylation of all types of N-phenylsulfonyl amides, the chemoselective deprotection of the O-allyl/benzyl/tosyl/t-butyldimethylsilyl (TBDMS) groups, the reduction of the nitro groups, the partial reduction of the carbonyl groups of diketone, the reductive ligand coupling of the diphenyliodonium salt, and the reductive diaryl coupling of the dihalogen compounds via anion radical species with good to excellent yields under mild conditions. This system is a very attractive method for several reasons (simplicity, good availability, low cost, and easy operation) and would be particularly useful for large-scale reactions.