The Stereochemistry of the Reactions between Palladacycle Complexes and Primary Alkyl Iodides

19 January 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


As an important elementary step in organometallic chemistry, the alkylation reaction of palladacycle complexes and alkyl halides has attracted much attention in recent years due to their presence as key step in palladium catalyzed C-H alkylation reactions. In principle, several alkylation mechanisms, such as the stereoinvertive SN2-type mechanism and the stereoretentive oxidative addition (OA) mechanism can be operated, and mechanistic insights can be obtained from the stereochemical outcomes of these alkylation reactions. Previous stereochemical investigations on the alkylation reaction of palladacycle complexes mainly focused on the use of chiral secondary alkyl halides as stereochemical probes, leaving more synthetically relevant primary alkyl iodides untouched. In this work, deuterium-labeled primary alkyl iodides were selected as a stereochemical probe, and their reaction with C,C- and C,X-type palladacycle complexes, namely Catellani-type palladacycle intermediates and directing group (DG)-coordinated palladacycle complexes, were investigated both experimentally and computationally to elucidate the alkylation mechanism. We found that, the C,C-ligated palladacycle intermediates undergo alkylation through the SN2-Pd mechanism, while the C,X-ligated 8-aminoquinolin-derived palladacycle complex favors an OA mechanism. In addition, the 2-phenylpyridine-derived C,X-type palladacycle dimer complex was found to react through the SN2-Pd mechanism due to its stable dimer structure and the d8-d8 interaction between two palladium atoms.


Primary alkyl iodides
Reaction mechanism

Supplementary materials

Supporting Information for The Stereochemistry of the Reactions between Palladacycle Complexes and Primary Alkyl Iodides
Detailed experimental procedure, NMR spectra, and DFT computational results are available.


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.