Organic Letters
Letter
a
Scheme 8. Synthetic Transformations
ORCID
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
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We thank Nippoh Chemical Co. for generous financial support
and gift of DIH. We acknowledge the technical staff of the
Comprehensive Analysis Center of ISIR, Osaka University
(
Japan). We thank Prof. A. Osuka (Kyoto University) and
Prof. T. Nishimura (Osaka City University) for X-ray
crystallographic analysis, and Prof. H. Sasai (Osaka University)
for valuable discussion.
a
(
i) NaOEt (8.0 equiv), dioxane/H O, rt, 12 h, 80% yield. (ii) TBSCl
2
REFERENCES
(
4.4 equiv), n-BuLi (2.2 equiv), THF, 0 °C to rt, 2 h, 71% yield. (iii)
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MeMgBr (6.0 equiv), NiCl (dppf) (20 mol %), Et O, reflux, 12 h,
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7
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2
2
6% yield. (iv) TBAF (2.4 equiv), pyridine (2.4 equiv), THF, rt, 12 h,
4% yield.
yielded bisnaphthoquinone derivative 16 in 80% yield (Scheme
B). The resulting 16 is a key precursor for natural products,
which has been successfully synthesized by Kozlowsky’s
8
2
1
5
group.
9
(
In summary, we have achieved multiple iodination and novel
direct triflation of BINOL derivatives. A series of multiple
triflated BINOL derivatives was successfully synthesized by
control of equivalent amounts of DIH and TfOH. The
developed method can be used to introduce up to eight TfO
groups in a single operation to afford a highly oxidized
compound. The mixing of DIH and TfOH generates
Carosati, E. QSAR Modeling and Data Mining Link Torsades de
Pointes Risk to the Interplay of Extent of Metabolism, Active
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(
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Palladium-catalyzed directing group-assisted C8-triflation of naph-
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(5) Huang, H.; Wu, Y.; Zhang, W.; Feng, C.; Wang, B. Q.; Cai, W.
F.; Hu, P.; Zhao, K. Q.; Xiang, S. K. Copper-Catalyzed Regioselective
C-H Sulfonyloxylation of Electron-Rich Arenes with p-Toluenesul-
fonic Acid and Sulfonyloxylation of Aryl(mesityl)iodonium Sulfo-
nates. J. Org. Chem. 2017, 82, 3094.
hypervalent iodine species I(OTf) through disproportionation
3
7
(
of TfOI to promote triflation of aromatic C−H bonds. The
resulting triflate compounds are expected to be valuable
intermediate for the synthesis of chiral ligands and natural
products.
(
ASSOCIATED CONTENT
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S
Supporting Information
(
6) Reported examples of C−H sulfonyloxylation of arene:
(
a) Borgel, J.; Tanwar, L.; Berger, F.; Ritter, T. Late-Stage Aromatic
̈
Experimental procedures, characterization for new
compounds including copies of NMR spectra, X-ray
crystallographic data for 3 (CCDC 1905896), for 7
C−H Oxygenation. J. Am. Chem. Soc. 2018, 140, 16026. (b) Koser, G.
F.; Telu, S.; Laali, K. K. Oxidative-substitution reactions of polycyclic
aromatic hydrocarbons with iodine(III) sulfonate reagents. Tetrahe-
dron Lett. 2006, 47, 7011.
(
(
CCDC 1905894), for 8 (CCDC 1905893), and for 11
(
7) (a) Parmar, D.; Sugiono, E.; Raja, S.; Rueping, M. Complete
Field Guide to Asymmetric BINOL-Phosphate Derived Brønsted
Acid and Metal Catalysis: History and Classification by Mode of
Activation; Brønsted Acidity, Hydrogen Bonding, Ion Pairing, and
Metal Phosphates. Chem. Rev. 2014, 114, 9047. (b) Allen, S. E.;
Walvoord, R. R.; Padilla-Salinas, R.; Kozlowski, M. C. Aerobic
Copper-Catalyzed Organic Reactions. Chem. Rev. 2013, 113, 6234.
(c) Brunel, J. M. BINOL: A Versatile Chiral Reagent. Chem. Rev.
2005, 105, 857. (d) Pu, L. 1,1‘-Binaphthyl Dimers, Oligomers, and
Polymers: Molecular Recognition, Asymmetric Catalysis, and New
Materials. Chem. Rev. 1998, 98, 2405.
Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: +44 1223 336033.
AUTHOR INFORMATION
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(8) Kamei, T.; Shibaguchi, H.; Sako, M.; Toribatake, K.; Shimada, T.
Scandium triflate-catalyzed 6,6’-diiodination of 2,2’-dimethoxy-1,1’-
binaphthyl with 1,3-diiodo-5,5-dimethylhydantoin. Tetrahedron Lett.
2012, 53, 3894.
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Org. Lett. XXXX, XXX, XXX−XXX