Transition metal catalyzed C–C bond forming chemistry is one of the most utilized and powerful synthetic methods available for making fine chemicals. Precious metal catalysts have dominated due to their high activity and fortuitous two-electron redox cycles. However, their high cost and low earth-abundance have prompted more recent focus on base metal systems. Nickel has been shown to be quite capable of performing similar and even new transformations. However, unlike precious metals, nickel catalysis tends to suffer from unproductive one-electron pathways which can hinder catalysis. Pincer-type frameworks have been shown to be a vital class of ligands in catalysis and study of fundamental reactivity. Main group metalloligand scaffolds have shown promise in enhancing and turning on new types of reactivity at transition metals, often promoting two-electron chemistry. Among these, Lewis acidic Group 13 metals have garnered much attention due to their ability to act as strong σ-acceptors and potential ambiphilic character. A new untethered pincer-type Ni(PAlP) bimetallic system has been developed in which an open ligand framework allows direct access to the Ni−Al interaction. The Ni(PAlP) system exhibited diverse modes of cooperative bond cleavage mediated by the two-site Ni−Al unit. Additionally, the Al metalloligand converts reversibly between alane and aluminyl forms induced by oxophilic donors and is concomitant with aryl group transfer from Al to Ni. This conversion was studied spectroscopically, giving mechanistic insight into the unique conversion. Computational analysis was also used to probe the unique bonding interaction between Ni and Al.

Cooperative bond activation in nickel complexes bearing PAlP pincer-type ligands

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.