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In conclusion, a one-step conversion of an internal
alkyne into a versatile a-iodoenone is realized by
using a combination of 2,6-dichloropyridine N-oxide,
a nucleophilic oxidant, and electrophilic NIS. With
electronically biased internal alkyne substrates, the re-
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À
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Experimental Section
General Procedure for the Preparation of 2 from 1
2,6-Dichloropyridine N-oxide (1.2 equiv.), NIS (1.5 equiv.),
and LiNTf2 (10 mol%) were added in this particular order
to a solution of the internal alkyne 1 (0.2 mmol) in dichloro-
methane (4 mL) in a vial at room temperature. The reaction
mixture was stirred at the same temperature for 24 h. Upon
completion, the mixture was concentrated and the residue
was purified by chromatography on silica gel (eluent: hex-
anes/ethyl acetate) to afford the desired product 2.
Acknowledgements
LZ thanks NSF (CHE-1301343) for financial support and
NIH shared instrument grant S10OD012077 for the purchase
of a 400 MHz NMR spectrometer.
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Adv. Synth. Catal. 2016, 358, 1417 – 1420