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Organic & Biomolecular Chemistry
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COMMUNICATION
Journal Name
DOI: 10.1039/C9OB00572B
2002, 11, 481.
OH
NH
5
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cat. Cu(II)
4a
+
5b
O
Ph
Ph
A
OH
Cu(II)
cat. Cu(II)
N
O
N
O
HO
Ph
Ph
Ph
Ph
6
B
C
H
OH
O
N
O
+
6ab
O
Ph
Ph
Ph
Ph
D
Scheme 3 Proposed reaction pathway
Conclusions
We have developed the synthetic method of benzoxazole
derivatives via the copper-catalyzed hydroamination of
alkynones with 2-aminophenols. The method can be
applicable to the synthesis of a wide range of functionalized
benzoxazole derivatives in good yields.
Preliminary
mechanistic experiments showed that the copper catalyst
would be involved in the hydroamination of alkynones with
2-aminophenos and the sequential intramolecular cyclization
of -iminoketones/elimination of acetophenone processes.
7
Conflicts of interest
There are no conflicts to declare.
Acknowledgements
This work was supported by a Grant-in-Aid for Scientific
Research (C) from the Japan Society for the Promotion of
Science (17K05794). We thank Mr. Keisuke Hashimoto and
Mr. Yoshiyuki Takahashi for their experimental supports.
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