Alkylzinc-mediated transmetallation of a calcium hydride

Abstract

The dimeric β-diketiminato calcium hydride, [(BDI)CaH]₂ (BDI = HC{(Me)CNDipp}₂; Dipp = 2,6-i-Pr₂C₆H₃), reacts with dialkylzinc reagents in a 1 : 2 ratio through sequential dialkyl(hydrido)zincate formation, calcium alkyl extrusion followed by further irreversible transmetallation of both the organyl and spectator BDI ligands, demonstrating the generality of this transmetallation strategy to access calcium alkyls or ligated zinc alkylated species. When the reaction is performed with dimethyl zinc and an organocalcium dimer with a pre-installed kinetically stabilising aryl substituent, [(BDI)Ca(μ-3,5-^tBu₂C₆H₃)(μ-H)Ca(BDI)], an organocalcium dimer comprised of differentiated alkyl and aryl functionalities can be accessed through hydride-for-methyl exchange, [(BDI)Ca(μ-3,5-^tBu₂C₆H₃)(μ-Me)Ca(BDI)].