Transition Metal-Nitrogen Multiple Bonds

David Wigley博士，亚利桑那大学化学系，由无机、生物无机和有机金属化学项目资助，研究过渡金属-氮多键的化学性质。有机氨基配体长期以来一直被用作辅助基团，以不同程度的空间保护和支持金属在其最高氧化态。然而，高活性的金属-亚胺基团并不为人所知。本研究的总体目标是更好地理解过渡金属-氮多键，并开发利用金属-亚胺基团的新方法。为了扩大它们的反应范围，将利用金属-亚硝基和-偶氮络合物开发新的金属介导的烯烃叠氮化反应，并对涉及亚胺中间体的化学计量和催化过程进行研究。这些叠氮化反应中可能的金属环中间体将通过独立的途径制备并作为机械探针进行检测。制备钌的新型亚胺配合物，并探讨其作为亚硝基[NR]转移试剂的应用。最后，金属-亚胺配合物将作为电环重排试剂用于合成有机化学。高活性的金属-亚胺基团是由过渡金属与带有一个额外取代基的氮键合而成，在一定条件下可以生成。这些金属-亚胺配合物激活甲烷中的碳氢键；在工业上重要的烯烃氢胺化反应和烯烃叠氮化反应中发挥核心作用；并被用于模拟加氢脱氮，丙烯氨氧化和腈还原催化的步骤。尽管活性金属-亚胺配合物很重要，但它们的数量仍然很少，性质也没有很好地系统化。本研究将制备一些新的亚胺配合物，开发新的激活金属亚胺基团的方法，并扩大其反应范围。

Dr. David Wigley, Chemistry Department, University of Arizona, is supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program for studies of the chemistry of transition metal-nitrogen multiple bonds. Organoimido ligands have long been used as ancillary groups to variable degrees of steric protection and to support metals in their highest oxidation states. However, highly reactive metal-imide moieties are not well known. The overall objective of this research is to gain a better understanding of transition metal-nitrogen multiple bonding and to develop new methods for utilizing metal-imido moieties. To extend the range of their reactions new metal-mediated alkene aziridination reactions will be developed using d2 metal-nitroso and -azo complexe with both stoichiometric and catalytic processes that involve imido intermediates being investigated. The probable metallacyclic intermediates in these aziridinations will be prepared by independent routes and examined as mechanistic probes. New imido complexes of ruthenium will be prepared and their utility as nitrene [NR] transfer reagents will be explored. Finally, metal-imido complexes will be developed as reagents for electrocyclic rearrangements of value to synthetic organic chemistry.Highly reactive metal-imide groups, which are composed of a transition metal bonded to a nitrogen that bears a single additional substituent, can be generated under certain conditions. These metal-imido complexes activate C-H bonds in methane; play a central role in the industrially important hydroamination of olefins and olefin aziridination; and have been used to model steps in hydrodenitrogenation, propylene ammoxidation, and nitrile reduction catalysis. Despite the importance of reactive metal-imido complexes, their numbers remain small and their properties are not well systematized. In this research a number of new imido complexes will be prepared, new methods for activating metal imido groups will be developed, and the range of their reactions will be extended.