10.1002/adsc.202100466
Advanced Synthesis & Catalysis
reduced pressure. The residue was purified by
column chromatography (petroleum ether/ethyl
acetate, 5:1) to afford the desired products 3.
Scheme 2 Control experiment.
Acknowledgements
Based on the above results and previous reports,[7]
a possible reaction mechanism was proposed as
shown in Scheme 3. Initially, sulfinic acid 2 reacts
with TBHP resulted in the formation of the sulfonyl
radical I. Then radical I chemoselective adds to the
C=C bond to afford the intermediate II, which
undergoes intramolecular cyclization to give the
benzyl radical intermediate III. Finally, intermediate
III undergoes oxidation to produce the cation IV,
which affords the desired product 3 via deprotonation.
We gratefully acknowledge the National Natural Science
Foundation of China (21901006) and the Anhui Provincial
Natural Science Foundation (1908085QB80) for providing the
financial support. We thank Dr. Yun Wei (AHNU) for her help
with the X-ray crystallographic analyses.
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Experimental Section
General Procedure for Synthesis of Products 3:
An oven-dried Schlenk tube (10 mL) was equipped
with a magnetic stir bar, 1 (0.1 mmol), sulfinic acids
2 (2.5 equiv, 0.25 mmol), Na2HPO4 (2 equiv, 0.2
mmol). The flask was evacuated and backfilled with
Ar for 3 times. Then 1 mL CH3NO2 was added
followed by TBHP (3 equiv, 0.3 mmol). The tube
was then sealed and the mixture was stirred for 24 h
at 100 oC under Argon (1 atm). After the reaction was
finished, the organic solvent was removed under the
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4
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