Chemistry - A European Journal
10.1002/chem.201800919
COMMUNICATION
drug. In addition, Lei and co-workers described an external Acknowledgements
oxidant-free anodic [3+2] annulation between phenols and
indols.[37] The possibility to isolate and characterize intermediates
S.R.W. thanks the DFG (Wa1276/14-1) for financial support. S.L.
and S.R.W. acknowledge the Carl-Zeiss Foundation for granting
a fellowship and the research network ELYSION, respectively. B.
A. F.-U. thanks the Impulsfonds Pre-HIKE (JGU Mainz), PASPA-
DGAPA UNAM, and CONACYT-Mexico for the support.
with such a structural feature supports the mechanistic proposal
that was stated for the formation of the 3-(2-hydroxyphenyl)-
benzofurans.
To furnish evidence of an easy scalability including the robustness
of the electro synthetic conversion, scale-up of cross-coupling
reaction 3c was performed. Similar to recently published
work,[19,25] we scaled the reaction up from a 25 mL beaker-type
cell (starting with 5.00 mmol of component A) to a 200 mL beaker-
type cell with 40.0 mmol component A (see Figure 1). The
application of the same electrolytic parameters yielded 3c as
analytically pure product in 59% (7.21 g) yield. The eightfold larger
electrolysis provided a slightly enhanced yield.
Keywords: C-C coupling • electrochemistry • furan •
heterocycles • oxidation
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In conclusion, a novel and innovative method to obtain (2-
hydroxyphenyl)benzofurans by anodic C,C cross-coupling
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benzofurans was demonstrated. These compounds can be
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