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Synfacts 2010(12): 1427-1427  
DOI: 10.1055/s-0030-1258932
Organo- and Biocatalysis
© Georg Thieme Verlag Stuttgart ˙ New York

Hypervalent Iodine(III) Organocatalysts

Contributor(s): Benjamin List, Saihu Liao
T. Dohi, N. Takenaga, K.-i. Fukushima, T. Uchiyama, D. Kato, S. Motoo, H. Fujioka, Y. Kita*
Ritsumeikan University, Shiga, Osaka University and Rigaku Corporation, Tokyo, Japan
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Publication History

Publication Date:
22 November 2010 (online)

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Significance

Several bis(iodoarene) compounds, such as 3, were designed and synthesized as organocatalysts for the oxidative spirocyclization of amide 1 to dienone 2. Bis(iodoarene) 3 exhibited high catalytic activity in this reaction and the cyclization product 2 could be isolated in 97% yield after 2.5 hours with 2 mol% catalyst. Using mono­iodoarene 4 rather than bis(iodoarene) 3 as the catalyst, only 52% yield of 2 was obtained after 12 hours even with a higher catalyst loading (10 mol%). A highly active hypervalent iodine(III) compound 5 was suggested to be generated in situ and this was proved in the stoichiometric ­reaction of 1 with preformed 5, where similar results were obtained under the same reaction conditions.