Journal of the American Chemical Society
COMMUNICATION
In summary, we have presented here the first examples of
internal redox processes involving aliphatic, nonbenzylic hydride
shift/cyclization sequences. The combination of benzylidene
barbituric acids and Sc(OTf)3 enabled us to trigger the desired
[1,5]-hydride shift from the aliphatic position, affording tetraline
derivatives. Substrates with a γ-dialkyl side chain underwent the
unexpected [1,6]-hydride/cyclization process to furnish indane
derivatives in good to excellent chemical yields (74-91%).
Although most of the internal redox reactions reported to date
involve the connection between the carbocation and the carba-
nion generated by the hydride shift, we have realized a novel
bond-formation reaction: nucleophilic attack from the aromatic
ring. Further investigations to develop new types of reactions by
exploiting the aliphatic hydride/cyclization sequence are under-
way in our laboratory.
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’ ASSOCIATED CONTENT
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12, 1732.
S
Supporting Information. Experimental procedures, ana-
b
lytical and spectroscopic data for new compounds, copies of
NMR spectra, and crystallographic data (CIF). This material is
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’ AUTHOR INFORMATION
Corresponding Author
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(9) For internal redox reactions catalyzed by Sc(OTf)3, see refs 2a,
2j, 4j, 4m, 6, and 7c.
(10) In order to obtain information about the reaction course, some
D-labeling experiments were conducted. The results are described in the
Supporting Information.
’ ACKNOWLEDGMENT
This work was partially supported by a Grant-in-Aid for Scientific
Research from the Japan Society for the Promotion of Science.
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