A Stereoselective Hydride Transfer Reaction With Contributions From Attractive Dispersion Force Control

DOI: 10.14469/hpc/9237 Metadata

Created: 2021-10-08 08:49

Last modified: 2022-04-07 19:45

Author: Henry Rzepa

License: Creative Commons: Public Domain Dedication 1.0

Funding: (none given)

Co-author: D. Christopher Braddock
Co-author: Krzysztof Oliwa
Co-author: Natnicha Limpaitoon

Description

Recently, we reported the addition of the lithium acetylide of alkyne 1 to adamantane carboxaldehyde 2 unexpectedly produced quantities of ynone 3 and adamantane methanol 4 (Figure 1).1 We invoked a hydride transfer in a six-membered chair-like transition state (TS A) from the initially formed secondary lithium alkoxide AdCH(C≡CtBu)OLi to still unreacted AdCHO to explain this observation. In line with this explanation, isolation of the expected addition product 5, and reformation of the lithium alkoxide in the presence of AdCHO 2 gave the same products.1 While the transfer of hydride from LiCCH (e.g., tBuLi)2 and LiNCH (e.g., LDA)3 motifs to carbonyl compounds are well precedented, to the best of our knowledge the above example constitutes the only known example of hydride transfer from a LiOCH atomic tetrad to a carbonyl compound.§ We noted that this outcome could be linked to the particular structure of this secondary alkoxide whereby steric compression of the adamantyl bearing sp3 centre is simultaneously relieved as the formation of conjugated ynone 3 acts as a thermodynamic driving force. While these two factors seem intuitive to the organic chemist, and where we invoked TS A with the adamantyl groups of both components in equatorial positions, herein we provide computational and experimental evidence for a third factor at work: attractive dispersion forces that help stabilise a transition state with the adamantyl grouping of the aldehyde occupying an axial position (TS B).

Members

DOIDescription
10.14469/hpc/9238 Computational data for transition state models for a Stereoselective Hydride Transfer Reaction with contributions from Attractive Dispersion Force Control
10.14469/hpc/9240 NMR, IR and MS spectroscopic data for a Stereoselective Hydride Transfer Reaction With Contributions From Attractive Dispersion Force Control
10.14469/hpc/9239 Computational and experimental data for Vibrational circular dichroism (VCD) analysis for a Stereoselective Hydride Transfer Reaction With Contributions From Attractive Dispersion Force Control
10.14469/hpc/9241 Crystallographic data for a Stereoselective Hydride Transfer Reaction with Contributions from Attractive Dispersion Force Control.

Associated DOIs

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References 10.1039/C6CC06395K Article: Stable bromoallene oxides Stable bromoallene oxides Stable bromoallene oxides Stable Bromoallene oxides
isReferencedBy 10.1039/D2CC01136K Published article: A stereoselective hydride transfer reaction with contributions from attractive dispersion force control
References 10.14469/hpc/8046 Student project report: Computational study of intermolecular hydride transfer from bulky lithium propargyl alkoxides to aldehydes

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