(±)-Polysiphenol and other Analogues via Symmetrical Intermolecular Dimerizations: a Synthetic, Spectroscopic, Structural and Computational Study
DOI: 10.14469/hpc/10703 Metadata
Created: 2022-07-25 17:50
Last modified: 2022-11-10 07:12
License: Creative Commons: Public Domain Dedication 1.0
Funding: (none given)
Co-author: Andrew White Co-author: D. Christopher Braddock Co-author: Gajan Santhakumar Co-author: Karim A. Bahou Co-author: Masih Nilforoushan Co-author: Tianyou He Co-author: Ziye Yang
Description
We report an improved total synthesis of 4,5-dibromo-9,10-dihydrophenanthrene-2,3,6,7-tetraol, (±)-polysiphenol, via intermolecular McMurray dimerization of 5-bromovanillin and subsequent intramolecular oxidative coupling as the key steps. The synthetic route is applicable to 4,5-dichloro-, 4,5-difluoro-halologues (as well as a 4,5-dialkyl-analogue). Distinctive AA’BB’ multiplets in their 1H NMR spectra for the dimethylene bridges of the dibromo- and dichloro- compounds reveal them to be room-temperature stable atropisomers, while for the difluoro-compound they present as a singlet. X-Ray crystal structure determinations of their tetramethylated synthetic precursors show atropisomeric twist angles of 48˚, 46˚ and 32˚ respectively, with the former representing the largest yet observed in any 4,5-disubstituted-9,10-dihydrophenanthrene. DFT computational studies reveal an unprecedented two-stage atropisomeric interconversion process involving time-independent asynchronous rotations of the dimethylene bridge and the biaryl axis for halologues containing chlorine or bromine, but a more synchronous rotation for the difluoro analogue.
Members
| DOI | Description |
|---|---|
| 10.14469/hpc/3883 | Computational data for (±)-Polysiphenol and other Analogues via Symmetrical Intermolecular Dimerizations: a Synthetic, Spectroscopic, Structural and Computational Study |
| 10.14469/hpc/10705 | Crystal structure data for (±)-Polysiphenol and other Analogues via Symmetrical Intermolecular Dimerizations: a Synthetic, Spectroscopic, Structural and Computational Study |
| 10.14469/hpc/10704 | NMR Data for (±)-Polysiphenol and other Analogues via Symmetrical Intermolecular Dimerizations: a Synthetic, Spectroscopic, Structural and Computational Study |
Associated DOIs
| Current dataset ... | DOI | Description |
|---|---|---|
| isReferencedBy | 10.1021/acs.jnatprod.2c00749 | Article: (±)-Polysiphenol and Other Analogues via Symmetrical Intermolecular Dimerizations: A Synthetic, Spectroscopic, Structural, and Computational Study |