Insertion of Imines and Carbon Monoxide into Manganese−Alkyl Bonds: Synthesis and Structure of a Manganese−α-Amino Acid Derivative
Bibliographic record
Abstract
Two new routes have been developed to generate manganese-chelated amides from imine and carbon monoxide building blocks. The reaction of (CO) 5 MnR (R = CH 3, Ph) with ( p -tolyl)(R 1 ) NR 2 (R 1 = H, t Bu; R 2 = alkyl, H) results in the generation of the cyclometalated imine complexes (CO) 4 Mn[η 2 -4-CH 3 -2-(C(R 1 ) NR 2 )-C 6 H 3 ] in 50−84% isolated yield. However, when the reaction of ( p -tolyl)(H)C NCH 3 with (CO) 5 MnCH 3 is performed in the presence of AlCl 3, the product of sequential carbon monoxide and imine insertion is generated in 35% yield: (CO) 4 Mn[η 2 -C(H)( p -tolyl)N(CH 3 )COCH 3 ]. The addition of PPh 3 to the latter complex results in replacement of a carbonyl ligand and formation of the isolable fac -(CO) 3 (PPh 3 )Mn[η 2 -C(H)( p -tolyl)N(CH 3 )COCH 3 ]. In an alternative route to metal-bound amides, the oxidative addition of the N-acyl iminium salt ( p -tolyl(H)C N(CH 3 )COPh + Cl - to (CO) 5 Mn - Na + has been found to lead to the generation of the product of subsequent CO insertion, (CO) 4 Mn[η 2 -COC(H)( p -tolyl)N(CH 3 )COPh]. The latter represents the first example of a acyl-bound transition-metal-chelated α-amino acid complex and has been characterized by X-ray crystallography. Preliminary reactivity studies demonstrate that (CO) 4 Mn[η 2 -COC(H)( p -tolyl)N(CH 3 )COPh] reacts with PPh 3 to generate the unchelated ci s -(CO) 4 (PPh 3 )Mn[COC(H)( p -tolyl)N(CH 3 )COPh], while reaction with NaBH 4 leads to the liberation of the amide ( p -tolyl)CH 2 N(CH 3 )COPh, rather than the amino acid residue.
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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) | 0.000 | 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".