Highly Reactive Low-valent Aluminium Complexes and their Application in Synthesis and Catalysis

ongoing

This ERC-CoG 2020 proposal, ALLOWE outlines a strategy for the development of low-valent aluminium systems through their synthesis, isolation, and reactivity investigation of neutral, ambiphilic, low-valent aluminium compounds, denoted “alumylenes”. Their dimeric form “dialumenes” featuring an aluminium-aluminium double bond will also be within the scope of the project. These low-valent aluminium species are expected to provide, along with greater understanding of the fundamental behaviour of low-valent aluminium, a varied and deep reactivity profile. These highly reactive compounds will offer a cheap, sustainable and non-toxic alternative to the current transition metal-based industrial chemical processes. The proposed scheme of work begins with the synthesis of neutral alumylenes and dialumenes, respectively. This will be achieved through the use of donor ligands (i.e. N-heterocyclic carbenes) and substituents with differing electronic and steric properties. With these compounds in hand, the reactivity towards small molecules will be investigated along with development of low-valent aluminium based catalysts. Furthermore, incorporation of transition metals into these aluminium systems will be targeted as these may possess unique and interesting properties. Established methodologies such as reductive dehalogenation or reductive dehydrohalogenation will provide access to novel low-valent aluminium compounds bearing bulky substituents and donor ligands. The synthetic portion of the work will also be supported by theoretical calculations. The outcome of ALLOWE will provide (i) in-depth insight and understanding into low-valent aluminium’s bonding nature, particularly emphasis laid on ambiphilic aluminium center (ii) plethora of striking reactivity towards transition metal free stoichiometric and catalytic activation of small molecules, and (iii) various potential applications in aluminium-based material chemistry.