Mechanistic studies of intramolecular aryl ether carbon-​oxygen bond activation by group 9 and 10 transition metal centers

Abstract

Aryl ether bond activation is of interest in the context of lignin conversion and org. methodol. To gain mechanistic insight, the intramol. reactivity of group 9 and 10 metals supported by a terphenyl diphosphine bearing an aryl Me ether was investigated. Ni°c and Rh^I were obsd. to activate aryl ether C-O bonds selectivity via oxidative addn. Non-selective activation of aryl and alkyl C-O bonds was obsd. at Ir^I. At Pd°c and Pt°c, alkyl C-O bond activation was obsd. through oxidative addn. With group 10 M^II halides, alkyl C-O bond activation was obsd. through Lewis-acid mediated alkyl halide elimination. Various modes of π-backbonding interactions between the central arene and the metal center were obsd. and these were correlated with trends in bond activation. Mechanistic details will be discussed.