Tuning the Electronic Properties of Azophosphines as Ligands and their Application in Base-Free Transfer Hydrogenation Catalysis

08 July 2024, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

The design and tuning of new ligands is crucial for unlocking new reactivity at transition metal centres. Azophosphines have recently emerged as a new class of 1,3-P,N ligands in ruthenium piano-stool complexes. This work shows that the azophosphine synthesis can tolerate N-aryl substituents with strongly electron-donating and electron-withdrawing para-R groups, and that the nature of this R group can affect the spectroscopic and structural properties of the azophosphines, as measured by NMR spectroscopy, UV-Vis spectroscopy, single crystal X-ray diffraction and DFT studies. Azophosphines are shown to be relatively weak phosphine donors, as shown by analysis of the 1JP–Se coupling constants of the corresponding azophosphine selenides, but the donor properties can be fine-tuned within this area of chemical space. Monodentate and bidentate Ru-azophosphine complexes were prepared, and their first use as catalysts was probed. The Ru-azophosphine complexes were found to promote the transfer hydrogenation of acetophenone to 1-phenylethanol without the requirement of a harsh base additive, and the bidentate complex was more active than the monodentate analogue.

Keywords

Azophosphine
Ligand
Catalysis
Coordination chemistry
Ruthenium
Phosphorus

Supplementary materials

Title
Description
Actions
Title
Supporting information for "Tuning the Electronic Properties of Azophosphines as Ligands and their Application in Base-Free Transfer Hydrogenation Catalysis"
Description
Supporting Information for "Tuning the Electronic Properties of Azophosphines as Ligands and their Application in Base-Free Transfer Hydrogenation Catalysis" Includes methods, caharacterisations data, catalysis experiments and summary of computational investigation.
Actions

Comments

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.