Combining Hammett σ constants for Δ-machine learning and catalyst discovery

Author(s)
V. Diana Rakotonirina, Marco Bragato, Stefan Heinen, O. Anatole von Lilienfeld
Abstract

We study the applicability of the Hammett-inspired product (HIP) Ansatz to model relative substrate binding within homogenous organometallic catalysis, assigning σ and ρ to ligands and metals, respectively. Implementing an additive combination (c) rule for obtaining σ constants for any ligand pair combination results in a cHIP model that enhances data efficiency in computational ligand tuning. We show its usefulness (i) as a baseline for Δ-machine learning (ML), and (ii) to identify novel catalyst candidates via volcano plots. After testing the combination rule on Hammett constants previously published in the literature, we have generated numerical evidence for the Suzuki-Miyaura (SM) C-C cross-coupling reaction using two synthetic datasets of metallic catalysts (including (10) and (11)-metals Ni, Pd, Pt, and Cu, Ag, Au as well as 96 ligands such as N-heterocyclic carbenes, phosphines, or pyridines). When used as a baseline, Δ-ML prediction errors of relative binding decrease systematically with training set size and reach chemical accuracy (∼1 kcal mol−1) for 20k training instances. Employing the individual ligand constants obtained from cHIP, we report relative substrate binding for a novel dataset consisting of 720 catalysts (not part of training data), of which 145 fall into the most promising range on the volcano plot accounting for oxidative addition, transmetalation, and reductive elimination steps. Multiple Ni-based catalysts, e.g. Aphos-Ni-P(t-Bu)3, are included among these promising candidates, potentially offering dramatic cost savings in experimental applications.

Organisation(s)
Computational Materials Physics
External organisation(s)
University of Toronto, Vector Institute for Artificial Intelligence, Technische Universität Berlin, Berlin Institute for the Foundations of Learning and Data (BIFOLD)
Journal
Digital Discovery
No. of pages
10
ISSN
2635-098X
DOI
https://doi.org/10.48550/arXiv.2405.07747
Publication date
10-2024
Peer reviewed
Yes
Austrian Fields of Science 2012
103006 Chemical physics
ASJC Scopus subject areas
Chemistry (miscellaneous)
Portal url
https://ucrisportal.univie.ac.at/en/publications/combining-hammett--constants-for-machine-learning-and-catalyst-discovery(e1057037-bc34-4000-b1b7-2619f5b35b5e).html