10.1002/adsc.201701178
Advanced Synthesis & Catalysis
solution of Na2S2O3 (2.0 mL) and extracted with DCM (3
× 5.0 mL). The organic layer was concentrated under
vacuum, the solvent was removed in vacuum, and the
product was purified by flash column chromatography
(ethyl acetate/ n-pentane = 1/2) to give 20.1 mg of 2a (78%
yield). The diastereomeric ratio of 2 was determined by 1H
NMR of the crude product mixture.
N
H
O
N
S
I2, PhI(OAc)2
visible light
O
S
H
1a
2a
– H+
I(OAc)
PIDA + I2
N
I
NH
O
S
O
S
Acknowledgements
H
E
B
D.Z., H.W., and H.C. are grateful to the China Scholarship
Council (CSC) for pre-doctoral stipends.
PhI(OAc)2 or I •
visible light
H
H
N
O
S
References
N
1,5-H migration
O
S
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D
N
I
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R’
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1. visible light
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R
R
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Scheme 2. Plausible mechanistic pathway.
Finally, we wondered about chemical product
modifications and decided to explore a reductive
conversion of 2g. To our delight, the first attempt was
successful and treatment of 2g with NiCl2 and NaBH4
in CH3OH/H2O at room temperature for 2 h gave the
1-(4-aminophenyl)-3-phenyl-4,5-dihydro-3H-isothia-
zole 1-oxide (3) in 93% yield (Scheme 3).
N
N
O
O
NiCl2 (5 mol %)
NaBH4 (2.0 equiv.)
S
S
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r.t., 2 h
H2N
O2N
2g
3
Scheme 3. Reduction 2g with NiCl2 and NaBH4.
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Experimental Section
General procedure for the preparation of 2a–o (as
illustrated for the synthesis of 2a)
Under argon, S-phenyl-S-(3-phenylpropyl) sulfoximine (1a,
25.9 mg, 0.1 mmol, 1.0 equiv.), PhI(OAc)2 (96.9 mg, 0.3
mmol, 3.0 equiv.) and iodine (25.4 mg, 0.1 mmol, 1.0
equiv.) were added into a 5.0 mL sealable reaction tube.
Then, DCE (1.0 mL) was added and the reaction was
stirred for 16 h under visible light. Subsequently, the
mixture was quenched by the addition of a sat. aqueous
3
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