A solid-supported arylboronic acid catalyst for direct amidation
DOI: 10.14469/hpc/5030 Metadata
Created: 2019-02-09 15:53
Last modified: 2019-02-18 16:26
License: Creative Commons: Public Domain Dedication 1.0
Funding: (none given)
Description
11B shifts were calculated for a wB97XD/aug-cc-pvdz scrf=(cpcm,solvent=water) model according to recent procedures18 Full data for calculations carried out to estimate the 11B NMR shifts for the solid phase dehydrated catalyst system can be found at DOI: 10.14469/hpc/5030. The structural results and 11B NMR shifts are shown for a single water complex of: a) phenylboronic acid derived boroxine which indicates only a weak dispersion complex with a long B-O bond of 2.77Å, as demonstrated by calculated shifts of δ29.8-29.3 ppm chemical shifts for this system; and b) phenylboronic acid derived dimeric anhydride which similarly forms a weak (3.28Å) single water complex with δ27.1-29.1 ppm. Only if the model is enlarged to three waters does a boron-bound isomer (B-O 1.65Å) appear as a minimum in the potential surface, with the four-coordinate boron at δ6 and the other trigonal boron at δ26.5. However, this isomer is 6.4 kcal/mol higher in free energy than a purely hydrogen bonded form containing only weak water-B interactions, B-O lengths 3.35Å, δ28.0-28.2 ppm.
Files
| Filename | Size | Type | Description |
|---|---|---|---|
| Search.qry | 3KB | application/octet-stream | Conquest Search Query |
| Query-results.jpg | 186KB | image/jpeg | Conquest search results as histogram plot of B...O intermolecular lengths |
Members
| DOI | Description |
|---|---|
| 10.14469/hpc/5027 | Diphenyldiboronic acid + 3H2O with B-O bond, ΔG = -969.017879 |
| 10.14469/hpc/5033 | diphenyldiboronic acid + 3H2O, with B-O bond dissociated ΔG=-969.028076, ΔΔG = -6.4 kcal/mol |
| 10.14469/hpc/5032 | 2,4,6-triphenyl-1,3,5,2,4,6-trioxatriborinane + H2O,with B-O bond dissociated. ΔG=-1071.465025 |
| 10.14469/hpc/5026 | Diphenyldiboronic acid + H2O, with B-O bond dissociated. ΔG=-816.194580 |
| 10.14469/hpc/5048 | Diphenyldiboronic acid + 4H2O with no B-O bond -1045.445854 -8.0 |
| 10.14469/hpc/5049 | Diphenyldiboronic acid + 4H2O with B-O bond -1045.433162 |
| 10.14469/hpc/5050 | Diphenyldiboronic acid + 3H2O with no B-O bond, Def2-TZVPPD -969.293871 8.4 |
| 10.14469/hpc/5051 | Diphenyldiboronic acid + 3H2O with B-O bond, Def2-TZVPPD -969.280497 |
Associated DOIs
| Current dataset ... | DOI | Description |
|---|---|---|
| References | 10.1039/C8CC09913H | Article:A solid-supported arylboronic acid catalyst for direct amidation |