10.1002/adsc.201800950
Advanced Synthesis & Catalysis
thaw method and irradiated under a white light (power:
0.07 W cm-2, λ > 420 nm) under argon atmosphere. The
final conversion was determined by GC-MS after 24 h
irradiation. To obtain the pure product, the mixture was
poured into 20 ml water and extracted by CH2Cl2. The
organic phase was dried over anhydrous MgSO4, and the
solvent removed under vacuum. The crude product was
then purified over a silica column chromatography to
afford the desired product using petroleum ether/ethyl
acetate (95:5 or 90:10) as eluent.
In summary, we have demonstrated a precise
energy band position tuning of molecular organic
photocatalysts for metal-free and visible light-driven
aromatic C-C formation reactions. Via a facile
heteroatom engineering on donor and acceptor
moieties, the reduction potential of the photocatalysts
could be gradually aligned to -2.04 V vs. SCE,
thereby leading to a high LUMO level. Various aryl
halides could be reduced to aryl radicals, which can
be coupled with heteroarene substrates to form the
final C-C coupled products. The designability of
molecular photocatalysts further promoted the
generation of linear polymer photocatalyst, showing
unfading activity for synthesizing a drug molecule by
two-step photocatalytic C-C coupling reaction under
visible light. We believe that this study can offer a
general design strategy to construct organic
Acknowledgements
The authors thank the Max Planck Society for financial support.
L.W., R.L. and W.H. thank the China Scholarship Council (CSC)
for scholarship. J.B. thanks the Alexander von Humboldt
foundation for postdoctoral research fellowship.
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6
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