Transition Metal-Nitrogen Multiple Bonds

点击翻译按钮获取中文摘要

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.