Trimerization and cyclization of reactive P-functionalities confined within OCO pincers
Persistent URL
Author(s)
Chinen, Beatrice L.
Hyvl, Jakub
Brayton, Daniel F.
Riek, Matthew M.
Yoshida, Wesley Y.
Chapp, Timothy W.
Rheingold, Arnold L.
Cain, Matthew F.
Date Issued
August 25, 2021
Abstract
In order to stabilize a 10–P–3 species with C2v symmetry and two lone pairs on the central phosphorus atom, a specialized ligand is required. Using an NCN pincer, previous efforts to enforce this planarized geometry at P resulted in the formation of a Cs-symmetric, 10π-electron benzazaphosphole that existed as a dynamic “bell-clapper” in solution. Here, OCO pincers 1 and 2 were synthesized, operating under the hypothesis that the more electron-withdrawing oxygen donors would better stabilize the 3-center, 4-electron O–P–O bond of the 10–P–3 target and the sp3-hybridized benzylic carbon atoms would prevent the formation of aromatic P-heterocycles. However, subjecting 1 to a metalation/phosphination/reduction sequence afforded cyclotriphosphane 3, resulting from trimerization of the P(I) center unbound by its oxygen donors. Pincer 2 featuring four benzylic CF3 groups was expected to strengthen the O–P–O bond of the target, but after metal–halogen exchange and quenching with PCl3, unexpected cyclization with loss of CH3Cl was observed to give monochlorinated 5. Treatment of 5 with (p-CH3)C6H4MgBr generated crystalline P-(p-Tol) derivative 6, which was characterized by NMR spectroscopy, elemental analysis, and X-ray crystallography. The complex 19F NMR spectra of 5 and 6 observed experimentally, were reproduced by simulations with MestreNova.
Journal
RSC Advances
Department
Chemistry
Citation
Chinen, B. L., Hyvl, J., Brayton, D. F., Riek, M. M., Yoshida, W. Y., Chapp, T. W., . . . Cain, M. F. (2021). Trimerization and cyclization of reactive P-functionalities confined within OCO pincers. RSC Advances, 11(46), 28602-28613. doi:10.1039/D1RA05926B
Publisher
Royal Society of Chemistry
Version of Article
Published article
DOI
10.1039/D1RA05926B
ISSN
2046-2069
Rights
CC BY 3.0
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2021-08-25_Chapp_Trimerization.pdf
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