Little is known about the reactivities of [PN‘−Fe−CH₂R] complexes. Until recently, there was little reason to suspect anything interesting about them. However, recent ROMP precatalysts of the [PN‘−Fe−CH₂R] formulation from the Milstein group justify fundamental coordination and reactivity studies and herein detail our own efforts.

Abstract

Neutral three-coordinate iron alkylidenes of the form PN−Fe=CHR have been proposed as viable candidates for alkene metathesis. Indeed, during the final stages of preparing this current study, a separate report disclosed that dearomatized PN−Fe-alkyl complexes are active precatalysts for ring-opening metathesis polymerization (ROMP) of norbornene implicating PN−Fe=CHR species as possible intermediates. In yet another separate report, we prepared Zn analogues of PN−Fe-alkyl complexes and herein provide an account for the synthesis, characterization, and reactivity of some new iron complexes with the same tBu substituted PN platform.