The Chemistry of Organosamarium(II) and Related Complexes

该项目在无机，生物无机和有机 化学程序处理有机金属化学的 镧系金属，尤其是钐。有机钐 主要研究者已经证明复合物是 具有以下优点的异常强大的还原剂 可溶于许多常见的有机溶剂，其中 它们会产生各种极不寻常的 有机分子对这些配合物的进一步研究是 预计两者都会更好地定义其作为合成物的效用 试剂，并提供其化学性质的理解 反应性 本项目的目标是确定 控制有机镧系元素的特殊反应性（II） 络合物，特别是有机钐（II）络合物。的 特别感兴趣的是一系列相关的Sm（II）介导的 其中碳-碳双键或三键，或 氮-氮双键，被活化并与 CO以得到显著转化的产物。这些将 提供了极好的机会来探讨的原则， Sm（II）的反应性，因此将进行详细研究。这 化学将扩展到C-C键裂解反应， 使用Sm（II）-产生的二haptoacyl配合物， 直链烷基的环化。刘易斯效应 Sm（II）反应的酸中心将通过研究 还原转化中使用外部还原剂 存在双（五甲基环戊二烯）- 双（THF）钐（III）和双（五甲基环戊二烯）- （THF）铕（II）。这些实验的结果 研究了影响还原Sm-O键的方法 裂解，预计将导致还原转化 在钐中具有催化作用的系统。的合成 反应性桥连Sm（II）试剂将被探索 同样，这种不寻常的弯曲所产生的化学后果也会 二（五甲基环戊二烯）钐（II）的结构 用这种试剂活化烯烃。

This project in the Inorganic, Bioinorganic and Organometallic Chemistry Program deals with the organometallic chemistry of the lanthanide metals, especially samarium. Organosamarium complexes have been shown by the Principal Investigator to be unusually powerful reducing agents which have the advantage of being soluble in a number of common organic solvents, in which they effect a variety of highly unusual transformations of organic molecules. Further studies of these complexes are expected both to define better their utility as synthetic reagents and to provide an understanding of their chemical reactivity. The objective of this project is to determine the factors which control the special reactivity of organolanthanide(II) complexes, especially of organosamarium(II) complexes. Of special interest is a series of related Sm(II)-mediated reactions in which carbon-carbon double or triple bonds, or nitrogen-nitrogen double bonds, are activated and reacted with CO to give significantly transformed products. These will provide excellent opportunities to probe the principles of Sm(II) reactivity and therefore will be studied in detail. This chemistry will be extended to C-C bond cleavage reactions and the use of Sm(II)-generated dihaptoacyl complexes to effect cyclization of straight-chain alkyls. The effect of the Lewis acid center on Sm(II) reactions will be examined by studying reductive transformations using an external reductant in the presence of bis(pentamethylcyclopentadiene)- bis(THF)samarium(III) and bis(pentamethylcyclopentadiene)- (THF)europium(II). The results of these experiments, together with studies of methods for effecting reductive Sm-O bond cleavage, are expected to lead to reductive transformation systems which are catalytic in samarium. The synthesis of reactive bridged bimetallic Sm(II) reagents will be explored also, as will the chemical consequences of the unusual bent structure of the bis(pentamethylcyclopentadiene)samarium(II) in the activation of alkenes by this reagent.