IRON-PROMOTED NITRENE-EXTRUSION REACTIONS IN 7-AZANORBORNADIENE DERIVATIVES

Nitrene-extrusion reactions are found to proceed in the thermolysis of a series of 7-azanorbornadiene derivatives (ANB) with diiron nonacarbonyl. Several intermediates of the structure (ANB)Fe(CO)3 are isolated, and their geometries are identified by spectroscopic analyses. The nitrene-extrusion reactions proceed in excellent yields for the iron complexes, in which electron-withdrawing substituents appear at the C-2, C-3, and N-7 positions of ANB. However, when some of these substituents are removed, the efficiency of nitrene extrusion is reduced. The rates of reactions are measured and found to be related directly to the electronic nature of the substituents. The Fe-N bond distance also changes with respect to the N-7 substituents, as evidenced by the single-crystal X-ray diffraction analyses of (2,3-dicarbomethoxy-7-(methylsulfonyl)-ANB)Fe(CO)3 and (2,3-dicarbomethoxy-7-phenyl-ANB)Fe(CO)3. The benzofused ANB derivatives react in an analogous manner, whereas the 7-azanorbornene derivatives do not undergo the processes of deamination. © 1990, American Chemical Society. All rights reserved.