Ruthenium-Catalyzed [2 + 2] versus Homo Diels–Alder [2 + 2 + 2] Cycloadditions of Norbornadiene and Disubstituted Alkynes: A DFT Study
Bibliographic record
Abstract
The ruthenium-catalyzed [2 + 2] and homo Diels-Alder [2 + 2 + 2] cycloadditions of norbornadiene with disubstituted alkynes are investigated using density functional theory (DFT). These DFT calculations provide a mechanistic explanation for observed reactivity trends with different functional groups. Alkynyl phosphonates and norbornadiene form the [2 + 2 + 2] cycloadduct, while other functionalized alkynes afford the respective [2 + 2] cycloadduct, in excellent agreement with experimental results. The computational studies on the potential energy profiles of the cycloadditions show that the rate-determining step for the [2 + 2] cycloaddition is the final reductive elimination step, but the overall rate for the [2 + 2 + 2] cycloaddition is controlled by the initial oxidative cyclization. Two distinct mechanistic pathways for the [2 + 2 + 2] cycloaddition, cationic and neutral, are characterized and reveal that Cp*RuCl(COD) energetically prefers the cationic pathway.
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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| 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".