Dialkyl Ethers and Sacrificial Zinc: Oxide Synthons for Calcium tert-Butoxide Formation

Kyle G. Pearce; Agustin Morales Aguilar; Michael S. Hill; Claire L. McMullin

doi:10.1002/anie.9268230

Dialkyl Ethers and Sacrificial Zinc: Oxide Synthons for Calcium tert-Butoxide Formation

Kyle G. Pearce
, Agustin Morales Aguilar
, Michael S. Hill
, Claire L. McMullin

Research output: Contribution to journal › Article › peer-review

Abstract

The calcium hydride, [(BDI)CaH] ₂ (BDI = HC{C(Me)NDipp} ₂, where Dipp = 2,6-i-Pr ₂C ₆H ₃), reacts with Znt-Bu ₂ to form the monomeric and toluene-stabilised calcium dialkyl(hydrido)zincate, [(BDI)Ca-μ-H-Zn(t-Bu) ₂(η ⁶-C ₇H ₈)]. When treated with dialkyl ethers, this compound initiates a sequence of twofold ether deprotonation and dealkylation by alkene extrusion, from which the resultant oxide dianion is sequestered as a tert-butoxide anion. Through a combination of experiment and theory, this completely selective C─O bond forming process is deduced to result from the formation of incipient calcium tert-butyl and hydride intermediates, and subsequent tertiary carbenium ion generation enabled by reduction of Zn(II) to elemental zinc. The overall transformation, therefore, may be rationalised as a consequence of latent extreme basicity in harness with a cooperative redox process that is intrinsic to the combination of dissimilar constituent metals.

Original language	English
Article number	e9268230
Journal	Angewandte Chemie International Edition
Early online date	8 Sept 2026
DOIs	https://doi.org/10.1002/anie.9268230
Publication status	E-pub ahead of print - 8 Sept 2026

Data Availability Statement

The data that support the findings of this study are available in the Supporting Information of this article.

Funding

We thank the EPSRC (EP/X01181X/1, ‘Molecular ‐block Assemblies for Redox‐active Bond Activation and Catalysis: Repurposing the ‐block as 3‐elements’) and for their generous support of this research. This research made use of the Anatra High Performance Computing (HPC) Service at the University of Bath. Generative AI (ChatGPT) was used to render the image of an ingot of zinc included in the TOC graphic. s s d

Funders	Funder number
Engineering and Physical Sciences Research Council	EP/X01181X/1

Keywords

alkyl
calcium
density functional theory
heterobimetallic
hydride
zinc

ASJC Scopus subject areas

Catalysis
General Chemistry

Access to Document

10.1002/anie.9268230Licence: CC BY

Cite this

@article{521df3469f7f4f1b925ab9b5a7cb78e5,

title = "Dialkyl Ethers and Sacrificial Zinc: Oxide Synthons for Calcium tert-Butoxide Formation",

abstract = "The calcium hydride, [(BDI)CaH] 2 (BDI = HC\{C(Me)NDipp\} 2, where Dipp = 2,6-i-Pr 2C 6H 3), reacts with Znt-Bu 2 to form the monomeric and toluene-stabilised calcium dialkyl(hydrido)zincate, [(BDI)Ca-μ-H-Zn(t-Bu) 2(η 6-C 7H 8)]. When treated with dialkyl ethers, this compound initiates a sequence of twofold ether deprotonation and dealkylation by alkene extrusion, from which the resultant oxide dianion is sequestered as a tert-butoxide anion. Through a combination of experiment and theory, this completely selective C─O bond forming process is deduced to result from the formation of incipient calcium tert-butyl and hydride intermediates, and subsequent tertiary carbenium ion generation enabled by reduction of Zn(II) to elemental zinc. The overall transformation, therefore, may be rationalised as a consequence of latent extreme basicity in harness with a cooperative redox process that is intrinsic to the combination of dissimilar constituent metals.",

keywords = "alkyl, calcium, density functional theory, heterobimetallic, hydride, zinc",

author = "Pearce, \{Kyle G.\} and \{Morales Aguilar\}, Agustin and Hill, \{Michael S.\} and McMullin, \{Claire L.\}",

year = "2026",

month = sep,

day = "8",

doi = "10.1002/anie.9268230",

language = "English",

journal = "Angewandte Chemie International Edition",

issn = "1433-7851",

publisher = "John Wiley and Sons Inc.",

}

TY - JOUR

T1 - Dialkyl Ethers and Sacrificial Zinc: Oxide Synthons for Calcium tert-Butoxide Formation

AU - Pearce, Kyle G.

AU - Morales Aguilar, Agustin

AU - Hill, Michael S.

AU - McMullin, Claire L.

PY - 2026/9/8

Y1 - 2026/9/8

N2 - The calcium hydride, [(BDI)CaH] 2 (BDI = HC{C(Me)NDipp} 2, where Dipp = 2,6-i-Pr 2C 6H 3), reacts with Znt-Bu 2 to form the monomeric and toluene-stabilised calcium dialkyl(hydrido)zincate, [(BDI)Ca-μ-H-Zn(t-Bu) 2(η 6-C 7H 8)]. When treated with dialkyl ethers, this compound initiates a sequence of twofold ether deprotonation and dealkylation by alkene extrusion, from which the resultant oxide dianion is sequestered as a tert-butoxide anion. Through a combination of experiment and theory, this completely selective C─O bond forming process is deduced to result from the formation of incipient calcium tert-butyl and hydride intermediates, and subsequent tertiary carbenium ion generation enabled by reduction of Zn(II) to elemental zinc. The overall transformation, therefore, may be rationalised as a consequence of latent extreme basicity in harness with a cooperative redox process that is intrinsic to the combination of dissimilar constituent metals.

AB - The calcium hydride, [(BDI)CaH] 2 (BDI = HC{C(Me)NDipp} 2, where Dipp = 2,6-i-Pr 2C 6H 3), reacts with Znt-Bu 2 to form the monomeric and toluene-stabilised calcium dialkyl(hydrido)zincate, [(BDI)Ca-μ-H-Zn(t-Bu) 2(η 6-C 7H 8)]. When treated with dialkyl ethers, this compound initiates a sequence of twofold ether deprotonation and dealkylation by alkene extrusion, from which the resultant oxide dianion is sequestered as a tert-butoxide anion. Through a combination of experiment and theory, this completely selective C─O bond forming process is deduced to result from the formation of incipient calcium tert-butyl and hydride intermediates, and subsequent tertiary carbenium ion generation enabled by reduction of Zn(II) to elemental zinc. The overall transformation, therefore, may be rationalised as a consequence of latent extreme basicity in harness with a cooperative redox process that is intrinsic to the combination of dissimilar constituent metals.

KW - alkyl

KW - calcium

KW - density functional theory

KW - heterobimetallic

KW - hydride

KW - zinc

UR - https://www.scopus.com/pages/publications/105049743338

U2 - 10.1002/anie.9268230

DO - 10.1002/anie.9268230

M3 - Article

SN - 1433-7851

JO - Angewandte Chemie International Edition

JF - Angewandte Chemie International Edition

M1 - e9268230

ER -

Dialkyl Ethers and Sacrificial Zinc: Oxide Synthons for Calcium tert-Butoxide Formation

Abstract

Data Availability Statement

Funding

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Molecular s-block Assemblies for Redox-active Bond Activation and Catalysis: Repurposing the s-block as 3d-elements

Anatra HTC cluster

Cite this

Dialkyl Ethers and Sacrificial Zinc: Oxide Synthons for Calcium tert-Butoxide Formation

Abstract

Data Availability Statement

Funding

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Projects

Molecular s-block Assemblies for Redox-active Bond Activation and Catalysis: Repurposing the s-block as 3d-elements

Equipment

Anatra HTC cluster

Cite this