Fe-catalyzed conversion of N2 to N(SiMe3)3 via an Fe-hydrazido resting state
The catalytic conversion of N2 to N(SiMe3)3 by homogenous transition metal compounds is a rapidly developing field, yet few mechanistic details have been experimentally elucidated for 3d element catalysts. Herein we show that Fe(PP)2(N2) (PP = R2PCH2CH2PR2; R = Me, 1Me; R = Et, 1Et) are highly effec...
Main Authors: | , , , , |
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Format: | Journal article |
Language: | English |
Published: |
American Chemical Society
2018
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Summary: | The catalytic conversion of N2 to N(SiMe3)3 by homogenous transition metal compounds is a rapidly developing field, yet few mechanistic details have been experimentally elucidated for 3d element catalysts. Herein we show that Fe(PP)2(N2) (PP = R2PCH2CH2PR2; R = Me, 1Me; R = Et, 1Et) are highly effective for the catalytic production of N(SiMe3)3 from N2 (using KC8/Me3SiCl), with the yields being the highest re-ported to date for Fe-based catalysts. We propose that N2 fixation proceeds via electrophilic N silylation and 1e– re-duction to form unstable FeI(NN-SiMe3) intermediates, which disproportionate to 1Me/Et and hydrazido FeII[N-N(SiMe3)2] species (3Me/Et); the latter act as resting states on the catalytic cycle. Subsequent 2e– reduction of 3Me/Et leads to N-N scission and formation of [N(SiMe3)2]– and putative anionic Fe imido products. These mechanistic results are supported by both experiment and DFT calculations. |
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