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Phenol oxidation with hypervalent iodine reagents leads to the formation of quinone-type products or iodonium ylides, depending on the structure of the phenol. Trapping of either product is possible with a suitable reagent, and this method is often employed in tandem with a second process.〔Moriarty, R. M.; Prakash, O. ''Org. React.'' 2001, ''57'', 327. 〕 ==Introduction== In the presence of hypervalent iodine(III) reagents such as iodobenzene diacetate (IBD) or iodobenzene di(trifluoroacetate) (IBTA), phenols undergo oxidation to either quinones.〔Tamura, Y.; Yakura, T.; Tohma, H.; Kikuchi, K.; Kita, Y. ''Synthesis'' 1989, 126.〕 or iodonium ylides.〔Prakash, O.; Tanwar, M. P.; Goyal, S.; Pahuja, S. ''Tetrahedron Lett.'' 1992, ''33'', 6519.〕 Phenols with an electron- withdrawing group in the ''para'' position form the latter, while most other phenols give the former (or derivatives thereof). Direct transformation of quinone products may occur through intramolecular Diels-Alder or Michael-type reactions. Bis(phenol) substrates undergo oxidative coupling under these conditions. Iodonium ylides are relatively stable, versatile compounds that undergo substitution and cycloaddition reactions. They are represented using two resonance forms, one zwitterionic (the "betaine" form) and the other neutral (the "ylide" form). ''(1)'' 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Phenol oxidation with hypervalent iodine reagents」の詳細全文を読む スポンサード リンク
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