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Record W2335183118 · doi:10.1021/jo501990u

Decarboxylation without CO<sub>2</sub>: Why Bicarbonate Forms Directly as Trichloroacetate Is Converted to Chloroform

2014· article· en· W2335183118 on OpenAlex
Graeme W. Howe, Ronald Kluger

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.
fundA Canadian funder is recorded on the work.

Bibliographic record

VenueThe Journal of Organic Chemistry · 2014
Typearticle
Languageen
FieldBiochemistry, Genetics and Molecular Biology
TopicBiochemical Acid Research Studies
Canadian institutionsUniversity of Toronto
FundersNatural Sciences and Engineering Research Council of Canada
KeywordsDecarboxylationChemistrySolvationBicarbonateCarboxylateCatalysisCarbanionBond cleavageCleavage (geology)Reaction mechanismComputational chemistryPhotochemistryOrganic chemistryMolecule

Abstract

fetched live from OpenAlex

Patterns in the observed catalysis of decarboxylation reactions required us to conclude that these reactions involve initial hydration of the carboxylate and subsequent loss of bicarbonate. This raises the important and general question of why CO2 is not formed directly. Reaction profiles for the direct decarboxylation of trichloroacetate were generated with DFT calculations and show no significant barrier to the recombination of the incipient trichloromethide and CO2. In contrast, cleavage of the C-C bond from the hydrated intermediate shows a substantial barrier to recombination that allows separation of the products. The free energy of the transition state for C-C bond cleavage following hydration is higher than the free energy for formation of the hydrate and is comparable to the free energy of activation for direct decarboxylation. Thus, we conclude that the advantage of the hydrolytic pathway is that it provides a means to overcome the problems of separation and solvation that hinder the direct loss of CO2. The resulting concepts are readily extended to explicating the mechanisms of processes in enzymic catalysis as well as providing a basis for producing C-C bonds by the addition of derivatives of carbanions to carbonates.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.001
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.003
Threshold uncertainty score0.682

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.001
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0010.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.007
GPT teacher head0.247
Teacher spread0.240 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it