Electronic and Steric Effects of the ProPhos Ligand Family for Nickel-Catalyzed Suzuki–Miyaura Coupling of Heteroaromatics
Bibliographic record
Abstract
High Resolution Image Download MS PowerPoint Slide Nickel-catalyzed Suzuki–Miyaura coupling (Ni-SMC) reactions offer a cost-effective approach for active pharmaceutical ingredient (API) synthesis but remain constrained by their limited compatibility with heteroaromatic substrates and the need for high catalyst loadings. Our laboratory recently developed the ProPhos ligand, which significantly addresses these challenges. In this study, we systematically investigate the electronic and steric effects of the ProPhos ligand framework. Evaluation of over 20 ProPhos derivatives, alongside representative monodentate and bidentate phosphine ligands, reveals that the beneficial influence of the tethered hydroxyl group is general. Other nucleophilic substituents were less effective, and variations in the three-carbon linker length compromised the catalytic efficiency. Increased steric bulk on phosphorus decreased reactivity, whereas electron-donating substituents such as para -tolyl enhanced performance; in contrast, replacing aryl groups with cyclohexyl groups proved detrimental. Finally, the application of the optimized ligand, ProPhos*, to a range of previously challenging substrates demonstrated the robustness and efficiency of Ni-SMC at low catalyst loading.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".