Frontiers of organo- and hydridocalcium chemistry

• Main Author: Wilson, Andrew
• Other Authors: Hill, Michael
• Published: University of Bath 2018
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.767564

In contrast to magnesium, investigations of the reactivity of well-defined and solvent-free heteroleptic calcium hydride species are somewhat limited. Chapter 2 describes an investigation into the synthesis and subsequent reactivity of a base-free β-diketiminatocalcium hydride species. An initial study indicated this solvent free species was more reactive than its THF solvated analogue, albeit via the same σ-bond metathesis and π-insertion pathways. The insertion chemistry of the C=C bonds of a range of n-alkenes into the Ca-H bond is described in Chapter 3. This reactivity has yielded the first isolated heteroleptic calcium n-alkyl species. The subsequent stochiometric and catalytic hydrogenation of these species is also reported. Chapter 4 reports that the unprecedented nucleophilic alkylation of benzene may be achieved with the highly nucleophilic calcium alkyls described in Chapter 3. Mechanistic and computational analysis suggests that the cleavage of the dimeric compounds to provide coordinatively unsaturated monomeric species is paramount. This chapter concludes with a study of the reactivity of the parent hydride with benzene and a variety of polyaromatic molecules and annulenes, to yield several species containing doubly reduced cyclooctatetradiene, naphthalene and anthracene fragments.