Rapid Intermolecular C–H Activation of Aromatic Substrates at a Cationic, Electrophilic Molybdenum(VI) Nitrido Complex: Mechanistic Nuance in C–H Amination
Bibliographic record
Abstract
When the cationic, octahedral terminal nitrido complex of Mo(VI) supported by a diborate pentadentate ligand is generated in the absence of trapping nucleophiles, it activates the C(sp 2 )–H bonds of simple arenes, forming the cationic imido complexes [[ Ar Mo V ]═NR] + (R = H; PhX, X = H, o,m,p -F). Density Functional Theory computations and experimental studies support a novel mechanism with homolytic aromatic substitution character, wherein electrophilic attack of the arene π system initiates N–C bond formation, but use of electrons from the Mo≡N triple bond completes bond formation through an open-shell singlet transition state that formally reduces the metal center to Mo(V) and imbues the arene ring with radical character. This transition state is enthalpically 15 kcal mol –1 lower in energy than the “Wheland-type” transition state common to electrophilic aromatic substitution paths proposed in related systems. Subsequent intramolecular transfer of the arene hydrogen to the imido nitrogen atom leads to the cationic Mo(IV) anilido complex [[ Ar Mo IV ]-NHPh] +, which reacts with available [[ Ar Mo VI ]≡N] + by a proton-coupled electron transfer step to generate the 1:1 mixture of imido products [[ Ar Mo V ]=NR] + (R = H; C 6 H 4 X, X = H, o,m,p -F). This second phase of the mechanism is supported computationally and by a crossover experiment and is driven by significant coordination-induced bond weakening (CIBW) in the N–H bond of the [[ Ar Mo IV ]-NHPh] + . The novel mechanism of C–H addition to the electrophilic terminal nitrido opens new low energy pathways for the development of systems capable of catalytic nitrogen atom transfer to C–H bonds.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".