Rationally Improved Chiral Brønsted Acid for Catalytic Enantioselective Allylboration of Aldehydes with an Expanded Reagent Scope
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.
Bibliographic record
Abstract
One of the most useful reactions in organic synthesis, the stereocontrolled addition of allylic metal reagents to carbonyl compounds, provides access to enantiomerically enriched homoallylic alcohols related to the acetate, propionate, and other oxygen-containing functionalities present in a large number of biologically active natural products and pharmaceutical drugs. In the search for an ideal carbonyl allylation methodology, the catalytic enantioselective allylboration presents numerous advantages such as a high chemo-, diastereo-, and enantiocontrol with stable and nontoxic pinacol allylic boronates. This article reports a rationally improved diol x SnCl(4) complex as chiral protic acid catalyst, which provides unprecedented levels of enantioselectivity in the catalytic allylation, methallylation, crotylation, and 2-bromoallylation of aliphatic aldehydes. The new diol, p-F-Vivol (4b), enables a more active diol x SnCl(4) catalyst that can compete more effectively with the background uncatalyzed allylboration. The usefulness of this optimized catalytic allylboration methodology was demonstrated with an efficient synthesis of the naturally occurring pyranone (+)-dodoneine and to the preparation of biologically important exomethylene-gamma-lactones.
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 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 | 0.001 | 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) | 0.000 | 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 it