Synthesis and Reactivity of Complexes of Transition Metals in Negative Oxidation States

将研究两个广泛的主题--负氧化态高度还原的过渡金属卡宾络合物的合成，以及还原活化的芳香族配体的周环反应。研究的主要目的是回答三个广泛的问题：1)什么范围的pi受体配体能够稳定负氧化态的金属络合物？2)那些被证明能够稳定负氧化态的配体的可及络合物的范围有多广？以及3)从高度还原的金属中心到(通常不饱和的)pi受体配体的电子密度的pi回馈是否会激活配体朝向亲电性、偶联反应或其他前所未有的反应模式？一个重要的次要目标是开发在有机合成中具有潜在应用的新反应。%在化学部的无机、生物无机和有机金属项目中，匹兹堡大学的N·约翰·库珀博士将合成并研究在负氧化态下含有过渡金属的络合物的反应性。这些非常不寻常和高活性的化合物可能在有机合成中有应用。

Two broad topics will be investigated - the synthesis of highly reduced carbene complexes of transition metals in negative oxidation states, and pericyclic reactions of reductively activated aromatic ligands. The principal objective of the studies is to answer three broad questions: 1) What range of pi-acceptor ligands is capable of stabilizing complexes of metals in negative oxidation states?, 2) How wide is the range of accessible complexes for those classes of ligands which do prove to be capable of stabilizing negative oxidation states?, and 3) Will pi-back-donation of electron density from highly reduced metal centers to the (typically unsaturated) pi-acceptor ligands activate the ligands towards electrophiles, coupling reactions, or other unprecedented reactivity modes? An important secondary objective is the development of new reactions with potential applications in organic synthesis. %%% In this project in the Inorganic, Bioinorganic, and Organo- metallic Program of the Chemistry Division, Dr. N. John Cooper of the University of Pittsburgh will synthesize and study the reactivity of complexes containing transition metals in negative oxidation states. These very unusual and highly reactive compounds may have applications in organic synthesis.