二乙酸碘苯

二乙酸碘苯（PIDA）是化学式C 6H 5I(OCOCH 3) 2的超价碘化合物（英语：Hypervalent iodine），在有机化学中用作氧化剂。 二乙酸碘苯最早是由康拉德·威尔格罗德（英语：Conrad Willgerodt）于1892年通过碘苯和乙酸与过氧乙酸的混合物反应而成的： C6H5I   +   CH3CO3H   +   CH3CO2H   →   C6H5I(O2CCH3)2   +   H2O PIDA也可以由亚碘酰苯（英语：iodosobenzene）和冰醋酸反应而成： C6H5IO   +   2 CH3CO2H   →   C6H5I(O2CCH3)2   +   H2O 二乙酸碘苯最近的合成方式是直接由碘、乙酸和苯再加上作为氧化剂的过硼酸钠或过二硫酸钾一起反应而成： C6H6   +   I2   +   2 CH3CO2H   +   K2S2O8   →   C6H5I(O2CCH3)2   +   KI   +   H2SO4   +   KHSO4 PIDA分子是超价分子，它的碘原子形成了三个共价键。这个分子呈T形分子构型（英语：T-shaped molecular geometry），其中苯基占据水平位置，而乙酰氧基占据轴向位置，C-I-O键角低于90°。二乙酸碘苯的晶体结构是正交晶系，空间群 Pnn2。 PIDA可通过乙酰氧基的取代反应制备结构相似的试剂。举个例子，它在三氟乙酸中加热反应，可以得到二(三氟乙酸)碘苯（PIFA）： 产物PIFA则可以使酰胺在弱酸性环境，而不是以前需要的强碱性环境下发生霍夫曼降解反应。N-保护的天冬酰胺可以用PIDA脱羰，这可用于合成β-氨基-L-丙氨酸衍生物。 PIDA也可用于Suárez氧化反应中，这个反应可以把醇光解成环醚。这个反应被用于数个全合成中，如(−)-majucin、(−)-Jiadifenoxolane A和cephanolide A的全合成。 Willgerodt, C. Zur Kenntniss aromatischer Jodidchloride, des Jodoso- und Jodobenzols. Chem. Ber. 1892, 25 (2): 3494–3502 [2022-08-24]. doi:10.1002/cber.189202502221. （原始内容存档于2022-05-24） （德语）.  (1963) "Iodosobenzene Diacetate". Org. Synth. 43: 62; Coll. Vol. 5: 660.  Moriarty, Robert M.; Chany, Calvin J.; Kosmeder, Jerome W.; Du Bois, Justin. (Diacetoxyiodo)benzene. Encyclopedia of Reagents for Organic Synthesis. John Wiley & Sons. 2001. ISBN 9780470842898. doi:10.1002/047084289x.rd005m.pub2.  Hossain, Md. Delwar; Kitamura, Tsugio. Unexpected, Drastic Effect of Triflic Acid on Oxidative Diacetoxylation of Iodoarenes by Sodium Perborate. A Facile and Efficient One-Pot Synthesis of (Diacetoxyiodo)arenes. J. Org. Chem. 2005, 70 (17): 6984–6986. PMID 16095332. doi:10.1021/jo050927n.  Hossain, Md. Delwar; Kitamura, Tsugio. New and Direct Approach to Hypervalent Iodine Compounds from Arenes and Iodine. Straightforward Synthesis of (Diacetoxyiodo)arenes and Diaryliodonium Salts Using Potassium μ-Peroxo-hexaoxodisulfate. Bull. Chem. Soc. Jpn. 2007, 80 (11): 2213–2219. doi:10.1246/bcsj.80.2213.  Dohi, Toshifumi; Kita, Yasuyuki. Oxidizing Agents. Kaiho, Tatsuo (编). Iodine Chemistry and Applications. John Wiley & Sons. 2015: 277–302. ISBN 9781118878651.  Dohi, Toshifumi; Kita, Yasuyuki. Hypervalent Iodine. Kaiho, Tatsuo (编). Iodine Chemistry and Applications. John Wiley & Sons. 2015: 103–158. ISBN 9781118878651.  Lee, Chow-Kong; Mak, Thomas C. W.; Li, Wai-Kee; Kirner, John F. Iodobenzene diacetate. Acta Crystallogr. B. 1977, 33 (5): 1620–1622. doi:10.1107/S0567740877006694 .  Alcock, Nathaniel W.; Countryman, Rachel M.; Esperås, Steinar; Sawyer, Jeffery F. Secondary bonding. Part 5. The crystal and molecular structures of phenyliodine(III) diacetate and bis(dichloroacetate). J. Chem. Soc., Dalton Trans. 1979, 1979 (5): 854–860. doi:10.1039/DT9790000854.  (1988) "Hofmann Rearrangement Under Mildly Acidic Conditions Using [I,I-Bis(Trifluoroacetoxy)Iodobenzene: Cyclobutylamine Hydrochloride from Cyclobutanecarboxamide]". Org. Synth. 66; Coll. Vol. 8: 132.  Aubé, Jeffrey; Fehl, Charlie; Liu, Ruzhang; McLeod, Michael C.; Motiwala, Hashim F. 6.15 Hofmann, Curtius, Schmidt, Lossen, and Related Reactions. Heteroatom Manipulations. Comprehensive Organic Synthesis II 6. 2014: 598–635. ISBN 9780080977430. doi:10.1016/B978-0-08-097742-3.00623-6.  Wallis, Everett S.; Lane, John F. The Hofmann Reaction. Org. React. 1946, 3 (7): 267–306. doi:10.1002/0471264180.or003.07.  Surrey, Alexander R. Hofmann Reaction. Name Reactions in Organic Chemistry 2nd. Academic Press. 1961: 134–136. ISBN 9781483258683.  Zhang, Lin-hua; Kauffman, Goss S.; Pesti, Jaan A.; Yin, Jianguo. Rearrangement of Nα-Protected L-Asparagines with Iodosobenzene Diacetate. A Practical Route to β-Amino-L-alanine Derivatives. J. Org. Chem. 1997, 62 (20): 6918–6920. doi:10.1021/jo9702756.  Concepción, José I.; Francisco, Cosme G.; Hernández, Rosendo; Salazar, José A.; Suárez, Ernesto. Intramolecular hydrogen abstraction. Iodosobenzene diacetate, an efficient and convenient reagent for alkoxy radical generation. Tetrahedron Letters. 1984, 25 (18): 1953–1956. doi:10.1016/S0040-4039(01)90085-1.  Courtneidge, John L.; Lusztyk, Janusz; Pagé, Daniel. Alkoxyl radicals from alcohols. Spectroscopic detection of intermediate alkyl and acyl hypoiodites in the Suárez and Beebe reactions. Tetrahedron Letters. 1994, 35 (7): 1003–1006. doi:10.1016/S0040-4039(00)79950-3.  Dorta, R. L.; Francisco, C.G.; Freire, R.; Suárez, E. Intramolecular hydrogen abstraction. The use of organoselenium reagents for the generation of alkoxy radicals. Tetrahedron Letters. 1988, 29 (42): 5429–5432. doi:10.1016/S0040-4039(00)82887-7.  Condakes, Matthew L.; Hung, Kevin; Harwood, Stephen J.; Maimone, Thomas J. Total Syntheses of (−)-Majucin and (−)-Jiadifenoxolane A, Complex Majucin-Type Illicium Sesquiterpenes. Journal of the American Chemical Society. 2017, 139 (49): 17783–17786. doi:10.1021/jacs.7b11493.  Qing, Zhineng; Mao, Peng; Wang, Tie; Zhai, Hongbin. Asymmetric Total Syntheses of Cephalotane-Type Diterpenoids Cephanolides A–D. Journal of the American Chemical Society. 2022, 144 (23): 10640–10646. doi:10.1021/jacs.2c03978.