Development of Synthetic Organic Reactions Based on Novel Characteristic Behavior of Highly Coordinated Transition Metal Complexes

与基于主族元素的配合物相比，过渡金属配合物除了作为烷基化剂之外，还可以作为还原剂，因为配合物中的过量电子体系可以通过氧化加成与亲电试剂反应。我们计划研究过渡金属配合物的还原行为，发现从几种亲电试剂出发，可以直接还原生成有机金属试剂，即三丁基溴化铵试剂与碘甲基硫醚反应生成相应的硫甲基锰试剂。在该反应中，金属-卤素交换反应在-78 ℃下迅速进行，而碘甲硫醚与锰配合物的氧化加成反应主要在-20℃下进行。硫代甲基锰试剂与烯丙基溴、烯酮和醛反应。铬酸盐络合物也可还原烯丙基磷酸酯生成烯丙基铬试剂。我们还发现了铁催化的炔的碳锂化反应，其中产生了区域和立体化学定义的多取代乙烯基锂试剂。在该反应中，基于低价铁的酸盐型络合物被认为是实际的催化剂。

In contrast to ate-complexes based on main-group elements, transition-metal ate complexes are expected to be reductants besides alkylating agents, since the ate-complexes, the electron-excess system may react with electrophiles through the oxidative addition. We planed to investigate the reductive behavior of the transition metal ate complexes and found the direct and reductive generation of organometallic reagents starting from several electrophiles.Thus tributylmanganate reagent reacted with iodomethyl sulfides to produce the corresponding thiomethylmanganese reagents. In this reaction, metal-halogen exchange reaction proceeds rapidly even at-78℃, while the oxidative addition of iodomethyl sulfide to the manganese ate complex takes place predominantly at -20℃. Thiomethylmanganese reagents react with allyl bromides, enones, and aldehydes.Chromium ate complexes also reduce allyl phosphates to generate allylchromium reagents. We also found iron-catalyzed carbolithiation of alkynes, where the regio-and stereochemically defined multi-substituted vinyllithium reagents were produced. In this reaction, ate-type complex based on low valent iron is thought to be an actual catalyst.