Efficient synthesis of 4,6-bis(alkylamino) and -bis(arylimino)dibenzofurans. Pre-organized sterically bulky ligand systems for bimetallic coordination.

摘要

The development of hindered, rigid ligand systems for the construction of bimetallic coordination compounds is reported as models for putative bimetallic active sites of heterogeneous Ziegler-Natta catalyst systems. Our focus has been to make available efficient methodology for the synthesis of well-defined, sterically hindered organic templates to facilitate a more detailed investigation of novel supported bimetallic or polymetallic catalysts for olefin polymerization.;The efficient synthesis of bis(amido) and bis (imino) ligands based on a dibenzofuranyl template is reported. By making use of directed ortho-lithiation and electrophilic azide quench strategies as previously demonstrated, we have been able to develop a novel in situ Staudinger reaction for the formation of hindered 4,6-bis(amido) and 4,6-bis(imino) organic templates appropriate for bridging two interacting metal centres.