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Updated: May 14, 2025

Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
Alkylzinc-mediated transmetallation of a calcium hydride
Kyle G Pearce1, Mary F Mahon1, Michael S Hill1
1Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK. kgp29@bath.ac.uk.
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(micro-3,5-tBu2C6H3)(micro-H)Ca(BDI)], an organocalcium dimer comprised of differentiated alkyl and aryl functionalities can be accessed through hydride-for-methyl exchange, [(BDI)Ca(micro-3,5-tBu2C6H3)(micro-Me)Ca(BDI)].
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