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BibTex format

@article{Braddock:2022:10.1021/acs.jnatprod.2c00749,
author = {Braddock, D and Duran-Corbera, A and Nilforoushan, M and Yang, Z and He, T and Santhakumar, G and Bahou, K and Rzepa, H and Woscholski, R and White, A},
doi = {10.1021/acs.jnatprod.2c00749},
journal = {Journal of Natural Products},
pages = {2650--2655},
title = {(±)-Polysiphenol and other Analogues via Symmetrical Intermolecular Dimerizations:  a Synthetic, Spectroscopic, Structural and Computational Study},
url = {http://dx.doi.org/10.1021/acs.jnatprod.2c00749},
volume = {85},
year = {2022}
}
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TY  - JOUR
AB  - 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- and 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.
AU  - Braddock,D
AU  - Duran-Corbera,A
AU  - Nilforoushan,M
AU  - Yang,Z
AU  - He,T
AU  - Santhakumar,G
AU  - Bahou,K
AU  - Rzepa,H
AU  - Woscholski,R
AU  - White,A
DO  - 10.1021/acs.jnatprod.2c00749
EP  - 2655
PY  - 2022///
SN  - 0163-3864
SP  - 2650
TI  - (±)-Polysiphenol and other Analogues via Symmetrical Intermolecular Dimerizations:  a Synthetic, Spectroscopic, Structural and Computational Study
T2  - Journal of Natural Products
UR  - http://dx.doi.org/10.1021/acs.jnatprod.2c00749
UR  - http://hdl.handle.net/10044/1/101011
VL  - 85
ER  -
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