Rhodium-Catalyzed Addition of Boronic Acids to Vinylogous Imines Generated in situ
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Experimental Section
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Typical Procedure for the Rhodium-Catalyzed
Reactions of Boronic Acids with Sulfonylindoles
A 10-mL Schlenk tube was charged with [RhACTHNURTGNENG(U COD)Cl]2
(2.0 mg, 2 mol%), sulfonylindole 1 (0.2 mmol), boronic acid
2 (0.6 mmol), KOH (22.4 mg, 0.4 mmol) and then evacuated
under vacuum and placed under a nitrogen atmosphere. Di-
oxane (3 mL) and water (0.3 mL) were added subsequently.
The mixture was stirred at 1008C for 12 h. Then water
(15 mL) was added and the mixture was extracted with
CH2Cl2 (15 mL) for three times. The combined organic
phase was dried over Na2SO4 and concentrated under re-
duced pressure, the residue was subjected to flash chroma-
tography on silica gel (eluent: petroleum ether/ethyl acetate,
10:1) to yield the corresponding products 3.
2-Methyl-3-[(4-chlorophenyl)ACTHNUGRTNEUNG(phenyl)methyl]indole (3a):
Yield: 80%; white solid; mp 157–1608C; 1H NMR
(400 MHz, CDCl3): d=7.80 (s, 1H), 7.27–7.17 (m, 8H), 7.13
(d, J=8.0 Hz, 2H), 7.06 (t, J=7.5 Hz, 1H), 6.98 (d, J=
8.0 Hz, 1H), 6.90 (t, J=7.3 Hz, 1H), 5.69 (s, 1H), 2.20 (s,
3H); 13C NMR (100 MHz, CDCl3): d=143.5, 142.6, 135.4,
132.3, 132.0, 130.7, 129.8, 129.3, 128.5, 128.5, 126.5, 121.1,
119.6, 119.5, 113.7, 110.4, 47.4, 12.5; HR-MS: m/z=
330.1048, calcd. for C22H17NCl [MÀH]À: 330.1050.
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Acknowledgements
We are grateful to the financial support from National Natu-
ral Science Foundation of China (J0830415 & 21032003) and
Hunan Provincial Natural Science Foundation of China
(09JJ6024).
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